diff --git a/doc/src/pg_lib_properties.rst b/doc/src/pg_lib_properties.rst
index 65ce9cf940..256ed1cf82 100644
--- a/doc/src/pg_lib_properties.rst
+++ b/doc/src/pg_lib_properties.rst
@@ -49,6 +49,11 @@ event as atoms are migrating between sub-domains.
 
 -----------------------
 
+.. doxygenfunction:: lammps_memory_usage
+   :project: progguide
+
+-----------------------
+
 .. doxygenfunction:: lammps_get_mpi_comm
    :project: progguide
 
diff --git a/src/KOKKOS/atom_vec_angle_kokkos.cpp b/src/KOKKOS/atom_vec_angle_kokkos.cpp
index 662f09fe5a..ccb23064ed 100644
--- a/src/KOKKOS/atom_vec_angle_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_angle_kokkos.cpp
@@ -1724,9 +1724,9 @@ int AtomVecAngleKokkos::write_data_hybrid(FILE *fp, double *buf)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecAngleKokkos::memory_usage()
+double AtomVecAngleKokkos::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
 
   if (atom->memcheck("tag")) bytes += memory->usage(tag,nmax);
   if (atom->memcheck("type")) bytes += memory->usage(type,nmax);
diff --git a/src/KOKKOS/atom_vec_angle_kokkos.h b/src/KOKKOS/atom_vec_angle_kokkos.h
index 4fc71725b0..29b5ce8fc5 100644
--- a/src/KOKKOS/atom_vec_angle_kokkos.h
+++ b/src/KOKKOS/atom_vec_angle_kokkos.h
@@ -56,7 +56,7 @@ class AtomVecAngleKokkos : public AtomVecKokkos {
   int pack_data_hybrid(int, double *);
   void write_data(FILE *, int, double **);
   int write_data_hybrid(FILE *, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   void grow_pointers();
   int pack_comm_kokkos(const int &n, const DAT::tdual_int_2d &k_sendlist,
diff --git a/src/KOKKOS/atom_vec_atomic_kokkos.cpp b/src/KOKKOS/atom_vec_atomic_kokkos.cpp
index 995985b29d..e4a5f62c2c 100644
--- a/src/KOKKOS/atom_vec_atomic_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_atomic_kokkos.cpp
@@ -879,9 +879,9 @@ void AtomVecAtomicKokkos::write_data(FILE *fp, int n, double **buf)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecAtomicKokkos::memory_usage()
+double AtomVecAtomicKokkos::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
 
   if (atom->memcheck("tag")) bytes += memory->usage(tag,nmax);
   if (atom->memcheck("type")) bytes += memory->usage(type,nmax);
diff --git a/src/KOKKOS/atom_vec_atomic_kokkos.h b/src/KOKKOS/atom_vec_atomic_kokkos.h
index 212132ef60..2c682d4989 100644
--- a/src/KOKKOS/atom_vec_atomic_kokkos.h
+++ b/src/KOKKOS/atom_vec_atomic_kokkos.h
@@ -46,7 +46,7 @@ class AtomVecAtomicKokkos : public AtomVecKokkos {
   void data_atom(double *, tagint, char **);
   void pack_data(double **);
   void write_data(FILE *, int, double **);
-  bigint memory_usage();
+  double memory_usage();
 
   void grow_pointers();
   int pack_border_kokkos(int n, DAT::tdual_int_2d k_sendlist,
diff --git a/src/KOKKOS/atom_vec_bond_kokkos.cpp b/src/KOKKOS/atom_vec_bond_kokkos.cpp
index db56d58dff..b5a69f6fcb 100644
--- a/src/KOKKOS/atom_vec_bond_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_bond_kokkos.cpp
@@ -1148,9 +1148,9 @@ int AtomVecBondKokkos::write_data_hybrid(FILE *fp, double *buf)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecBondKokkos::memory_usage()
+double AtomVecBondKokkos::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
 
   if (atom->memcheck("tag")) bytes += memory->usage(tag,nmax);
   if (atom->memcheck("type")) bytes += memory->usage(type,nmax);
diff --git a/src/KOKKOS/atom_vec_bond_kokkos.h b/src/KOKKOS/atom_vec_bond_kokkos.h
index f38ade8f64..7f4d04c037 100644
--- a/src/KOKKOS/atom_vec_bond_kokkos.h
+++ b/src/KOKKOS/atom_vec_bond_kokkos.h
@@ -50,7 +50,7 @@ class AtomVecBondKokkos : public AtomVecKokkos {
   int pack_data_hybrid(int, double *);
   void write_data(FILE *, int, double **);
   int write_data_hybrid(FILE *, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   void grow_pointers();
   int pack_border_kokkos(int n, DAT::tdual_int_2d k_sendlist,
diff --git a/src/KOKKOS/atom_vec_charge_kokkos.cpp b/src/KOKKOS/atom_vec_charge_kokkos.cpp
index 9846d2f4f8..ce0751cb4f 100644
--- a/src/KOKKOS/atom_vec_charge_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_charge_kokkos.cpp
@@ -1048,9 +1048,9 @@ int AtomVecChargeKokkos::write_data_hybrid(FILE *fp, double *buf)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecChargeKokkos::memory_usage()
+double AtomVecChargeKokkos::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
 
   if (atom->memcheck("tag")) bytes += memory->usage(tag,nmax);
   if (atom->memcheck("type")) bytes += memory->usage(type,nmax);
diff --git a/src/KOKKOS/atom_vec_charge_kokkos.h b/src/KOKKOS/atom_vec_charge_kokkos.h
index 39d641b844..4d61b2a69c 100644
--- a/src/KOKKOS/atom_vec_charge_kokkos.h
+++ b/src/KOKKOS/atom_vec_charge_kokkos.h
@@ -51,7 +51,7 @@ class AtomVecChargeKokkos : public AtomVecKokkos {
   int pack_data_hybrid(int, double *);
   void write_data(FILE *, int, double **);
   int write_data_hybrid(FILE *, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   void grow_pointers();
   int pack_border_kokkos(int n, DAT::tdual_int_2d k_sendlist,
diff --git a/src/KOKKOS/atom_vec_dpd_kokkos.cpp b/src/KOKKOS/atom_vec_dpd_kokkos.cpp
index b112605859..70bd9e5827 100644
--- a/src/KOKKOS/atom_vec_dpd_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_dpd_kokkos.cpp
@@ -1830,9 +1830,9 @@ int AtomVecDPDKokkos::write_data_hybrid(FILE *fp, double *buf)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecDPDKokkos::memory_usage()
+double AtomVecDPDKokkos::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
 
   if (atom->memcheck("tag")) bytes += memory->usage(tag,nmax);
   if (atom->memcheck("type")) bytes += memory->usage(type,nmax);
diff --git a/src/KOKKOS/atom_vec_dpd_kokkos.h b/src/KOKKOS/atom_vec_dpd_kokkos.h
index e969a28cb8..71b0c85590 100644
--- a/src/KOKKOS/atom_vec_dpd_kokkos.h
+++ b/src/KOKKOS/atom_vec_dpd_kokkos.h
@@ -59,7 +59,7 @@ class AtomVecDPDKokkos : public AtomVecKokkos {
   int pack_data_hybrid(int, double *);
   void write_data(FILE *, int, double **);
   int write_data_hybrid(FILE *, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   void grow_pointers();
   int pack_comm_kokkos(const int &n, const DAT::tdual_int_2d &k_sendlist,
diff --git a/src/KOKKOS/atom_vec_full_kokkos.cpp b/src/KOKKOS/atom_vec_full_kokkos.cpp
index 89275c7067..e6f36d9994 100644
--- a/src/KOKKOS/atom_vec_full_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_full_kokkos.cpp
@@ -1588,9 +1588,9 @@ int AtomVecFullKokkos::write_data_hybrid(FILE *fp, double *buf)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecFullKokkos::memory_usage()
+double AtomVecFullKokkos::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
 
   if (atom->memcheck("tag")) bytes += memory->usage(tag,nmax);
   if (atom->memcheck("type")) bytes += memory->usage(type,nmax);
diff --git a/src/KOKKOS/atom_vec_full_kokkos.h b/src/KOKKOS/atom_vec_full_kokkos.h
index a2d4fa9cf4..4a5a61e913 100644
--- a/src/KOKKOS/atom_vec_full_kokkos.h
+++ b/src/KOKKOS/atom_vec_full_kokkos.h
@@ -50,7 +50,7 @@ class AtomVecFullKokkos : public AtomVecKokkos {
   int pack_data_hybrid(int, double *);
   void write_data(FILE *, int, double **);
   int write_data_hybrid(FILE *, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   void grow_pointers();
   int pack_border_kokkos(int n, DAT::tdual_int_2d k_sendlist,
diff --git a/src/KOKKOS/atom_vec_hybrid_kokkos.cpp b/src/KOKKOS/atom_vec_hybrid_kokkos.cpp
index 7c7f3c9826..baa7777907 100644
--- a/src/KOKKOS/atom_vec_hybrid_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_hybrid_kokkos.cpp
@@ -1198,9 +1198,9 @@ int AtomVecHybridKokkos::known_style(char *str)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecHybridKokkos::memory_usage()
+double AtomVecHybridKokkos::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   for (int k = 0; k < nstyles; k++) bytes += styles[k]->memory_usage();
   return bytes;
 }
diff --git a/src/KOKKOS/atom_vec_hybrid_kokkos.h b/src/KOKKOS/atom_vec_hybrid_kokkos.h
index 02f9044d73..3354735bf7 100644
--- a/src/KOKKOS/atom_vec_hybrid_kokkos.h
+++ b/src/KOKKOS/atom_vec_hybrid_kokkos.h
@@ -65,7 +65,7 @@ class AtomVecHybridKokkos : public AtomVecKokkos {
   void write_vel(FILE *, int, double **);
   int property_atom(char *);
   void pack_property_atom(int, double *, int, int);
-  bigint memory_usage();
+  double memory_usage();
 
   int pack_comm_kokkos(const int &n, const DAT::tdual_int_2d &k_sendlist,
                        const int & iswap,
diff --git a/src/KOKKOS/atom_vec_molecular_kokkos.cpp b/src/KOKKOS/atom_vec_molecular_kokkos.cpp
index 7e3cdbf5e3..ab29024438 100644
--- a/src/KOKKOS/atom_vec_molecular_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_molecular_kokkos.cpp
@@ -1987,9 +1987,9 @@ int AtomVecMolecularKokkos::write_data_hybrid(FILE *fp, double *buf)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecMolecularKokkos::memory_usage()
+double AtomVecMolecularKokkos::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
 
   if (atom->memcheck("tag")) bytes += memory->usage(tag,nmax);
   if (atom->memcheck("type")) bytes += memory->usage(type,nmax);
diff --git a/src/KOKKOS/atom_vec_molecular_kokkos.h b/src/KOKKOS/atom_vec_molecular_kokkos.h
index cede4f42a8..a356c6821c 100644
--- a/src/KOKKOS/atom_vec_molecular_kokkos.h
+++ b/src/KOKKOS/atom_vec_molecular_kokkos.h
@@ -56,7 +56,7 @@ class AtomVecMolecularKokkos : public AtomVecKokkos {
   int pack_data_hybrid(int, double *);
   void write_data(FILE *, int, double **);
   int write_data_hybrid(FILE *, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   void grow_pointers();
   int pack_comm_kokkos(const int &n, const DAT::tdual_int_2d &k_sendlist,
diff --git a/src/KOKKOS/atom_vec_sphere_kokkos.cpp b/src/KOKKOS/atom_vec_sphere_kokkos.cpp
index 6b62014e4a..dfae7fa547 100644
--- a/src/KOKKOS/atom_vec_sphere_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_sphere_kokkos.cpp
@@ -2765,9 +2765,9 @@ int AtomVecSphereKokkos::write_vel_hybrid(FILE *fp, double *buf)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecSphereKokkos::memory_usage()
+double AtomVecSphereKokkos::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
 
   if (atom->memcheck("tag")) bytes += memory->usage(tag,nmax);
   if (atom->memcheck("type")) bytes += memory->usage(type,nmax);
diff --git a/src/KOKKOS/atom_vec_sphere_kokkos.h b/src/KOKKOS/atom_vec_sphere_kokkos.h
index 3f6d34e8b2..676df431d1 100644
--- a/src/KOKKOS/atom_vec_sphere_kokkos.h
+++ b/src/KOKKOS/atom_vec_sphere_kokkos.h
@@ -69,7 +69,7 @@ class AtomVecSphereKokkos : public AtomVecKokkos {
   int pack_vel_hybrid(int, double *);
   void write_vel(FILE *, int, double **);
   int write_vel_hybrid(FILE *, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   int pack_comm_kokkos(const int &n, const DAT::tdual_int_2d &k_sendlist,
                        const int & iswap,
diff --git a/src/MISC/dump_xtc.cpp b/src/MISC/dump_xtc.cpp
index 9f2bbfe424..ba90f83310 100644
--- a/src/MISC/dump_xtc.cpp
+++ b/src/MISC/dump_xtc.cpp
@@ -310,9 +310,9 @@ int DumpXTC::modify_param(int narg, char **arg)
    return # of bytes of allocated memory in buf and global coords array
 ------------------------------------------------------------------------- */
 
-bigint DumpXTC::memory_usage()
+double DumpXTC::memory_usage()
 {
-  bigint bytes = Dump::memory_usage();
+  double bytes = Dump::memory_usage();
   bytes += memory->usage(coords,natoms*3);
   return bytes;
 }
diff --git a/src/MISC/dump_xtc.h b/src/MISC/dump_xtc.h
index 3fcc89f4ba..e242e7eef0 100644
--- a/src/MISC/dump_xtc.h
+++ b/src/MISC/dump_xtc.h
@@ -45,7 +45,7 @@ class DumpXTC : public Dump {
   void write_header(bigint);
   void pack(tagint *);
   void write_data(int, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   void write_frame();
 };
diff --git a/src/REPLICA/verlet_split.cpp b/src/REPLICA/verlet_split.cpp
index a5ed1a671d..389bd109e5 100644
--- a/src/REPLICA/verlet_split.cpp
+++ b/src/REPLICA/verlet_split.cpp
@@ -580,8 +580,8 @@ void VerletSplit::k2r_comm()
    memory usage of Kspace force array on master procs
 ------------------------------------------------------------------------- */
 
-bigint VerletSplit::memory_usage()
+double VerletSplit::memory_usage()
 {
-  bigint bytes = maxatom*3 * sizeof(double);
+  double bytes = maxatom*3 * sizeof(double);
   return bytes;
 }
diff --git a/src/REPLICA/verlet_split.h b/src/REPLICA/verlet_split.h
index b3ee87e580..f31ebdfa17 100644
--- a/src/REPLICA/verlet_split.h
+++ b/src/REPLICA/verlet_split.h
@@ -32,7 +32,7 @@ class VerletSplit : public Verlet {
   void setup(int);
   void setup_minimal(int);
   void run(int);
-  bigint memory_usage();
+  double memory_usage();
 
  private:
   int master;                        // 1 if an Rspace proc, 0 if Kspace
diff --git a/src/USER-DPD/nbin_ssa.cpp b/src/USER-DPD/nbin_ssa.cpp
index e3fa71aedf..21d630e789 100644
--- a/src/USER-DPD/nbin_ssa.cpp
+++ b/src/USER-DPD/nbin_ssa.cpp
@@ -120,9 +120,9 @@ void NBinSSA::bin_atoms_setup(int nall)
 
 /* ---------------------------------------------------------------------- */
 
-bigint NBinSSA::memory_usage()
+double NBinSSA::memory_usage()
 {
-  bigint bytes = NBinStandard::memory_usage(); // Count the parent's usage too
+  double bytes = NBinStandard::memory_usage(); // Count the parent's usage too
 
   return bytes;
 }
diff --git a/src/USER-DPD/nbin_ssa.h b/src/USER-DPD/nbin_ssa.h
index c738391d67..eb4b2db24c 100644
--- a/src/USER-DPD/nbin_ssa.h
+++ b/src/USER-DPD/nbin_ssa.h
@@ -47,7 +47,7 @@ class NBinSSA : public NBinStandard {
   void bin_atoms_setup(int);
   void bin_atoms();
 
-  bigint memory_usage();
+  double memory_usage();
 
   inline
   int coord2bin(const double & x,const double & y,const double & z, int &ixo, int &iyo, int &izo) const
diff --git a/src/USER-INTEL/nbin_intel.cpp b/src/USER-INTEL/nbin_intel.cpp
index 4a046bc845..3a2af740d8 100644
--- a/src/USER-INTEL/nbin_intel.cpp
+++ b/src/USER-INTEL/nbin_intel.cpp
@@ -241,7 +241,7 @@ void NBinIntel::bin_atoms(IntelBuffers<flt_t,acc_t> * buffers) {
 
 /* ---------------------------------------------------------------------- */
 
-bigint NBinIntel::memory_usage()
+double NBinIntel::memory_usage()
 {
   return NBinStandard::memory_usage() + maxatom*2*sizeof(int);
 }
diff --git a/src/USER-INTEL/nbin_intel.h b/src/USER-INTEL/nbin_intel.h
index d96f31885e..a7a28010ba 100644
--- a/src/USER-INTEL/nbin_intel.h
+++ b/src/USER-INTEL/nbin_intel.h
@@ -40,7 +40,7 @@ class NBinIntel : public NBinStandard {
   FixIntel *_fix;
   int *_atombin, *_binpacked;
   int _precision_mode;
-  bigint memory_usage();
+  double memory_usage();
 
   template <class flt_t, class acc_t>
   void bin_atoms(IntelBuffers<flt_t,acc_t> *);
diff --git a/src/USER-MOLFILE/dump_molfile.cpp b/src/USER-MOLFILE/dump_molfile.cpp
index e0e92f9339..f83477833e 100644
--- a/src/USER-MOLFILE/dump_molfile.cpp
+++ b/src/USER-MOLFILE/dump_molfile.cpp
@@ -452,9 +452,9 @@ int DumpMolfile::modify_param(int narg, char **arg)
    return # of bytes of allocated memory in buf and global coords array
 ------------------------------------------------------------------------- */
 
-bigint DumpMolfile::memory_usage()
+double DumpMolfile::memory_usage()
 {
-  bigint bytes = Dump::memory_usage();
+  double bytes = Dump::memory_usage();
   bytes += memory->usage(coords,natoms*3);
   bytes += sizeof(MFI);
   return bytes;
diff --git a/src/USER-MOLFILE/dump_molfile.h b/src/USER-MOLFILE/dump_molfile.h
index c99d1cc5ea..f07416cffa 100644
--- a/src/USER-MOLFILE/dump_molfile.h
+++ b/src/USER-MOLFILE/dump_molfile.h
@@ -51,7 +51,7 @@ class DumpMolfile : public Dump {
   virtual void write_header(bigint) {};
   virtual void pack(tagint *);
   virtual void write_data(int, double *);
-  virtual bigint memory_usage();
+  virtual double memory_usage();
   virtual void openfile();
 };
 
diff --git a/src/USER-VTK/dump_vtk.cpp b/src/USER-VTK/dump_vtk.cpp
index 59dba0d90d..794947f1b9 100644
--- a/src/USER-VTK/dump_vtk.cpp
+++ b/src/USER-VTK/dump_vtk.cpp
@@ -2309,9 +2309,9 @@ int DumpVTK::modify_param(int narg, char **arg)
    return # of bytes of allocated memory in buf, choose, variable arrays
 ------------------------------------------------------------------------- */
 
-bigint DumpVTK::memory_usage()
+double DumpVTK::memory_usage()
 {
-  bigint bytes = Dump::memory_usage();
+  double bytes = Dump::memory_usage();
   bytes += memory->usage(choose,maxlocal);
   bytes += memory->usage(dchoose,maxlocal);
   bytes += memory->usage(clist,maxlocal);
diff --git a/src/USER-VTK/dump_vtk.h b/src/USER-VTK/dump_vtk.h
index b9db1f88cb..28fcca78d6 100644
--- a/src/USER-VTK/dump_vtk.h
+++ b/src/USER-VTK/dump_vtk.h
@@ -77,7 +77,7 @@ class DumpVTK : public DumpCustom {
   int count();
   void pack(tagint *);
   virtual void write_data(int, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   int parse_fields(int, char **);
   void identify_vectors();
diff --git a/src/atom.cpp b/src/atom.cpp
index f28237cf74..831f7ac0b6 100644
--- a/src/atom.cpp
+++ b/src/atom.cpp
@@ -2586,9 +2586,9 @@ void *Atom::extract(const char *name)
    add in global to local mapping storage
 ------------------------------------------------------------------------- */
 
-bigint Atom::memory_usage()
+double Atom::memory_usage()
 {
-  bigint bytes = avec->memory_usage();
+  double bytes = avec->memory_usage();
 
   bytes += max_same*sizeof(int);
   if (map_style == 1)
diff --git a/src/atom.h b/src/atom.h
index 728d420596..bcb26b8a6f 100644
--- a/src/atom.h
+++ b/src/atom.h
@@ -341,7 +341,7 @@ class Atom : protected Pointers {
   // NOTE: placeholder method until KOKKOS/AtomVec is refactored
   int memcheck(const char *) {return 1;}
 
-  bigint memory_usage();
+  double memory_usage();
 
   // functions for global to local ID mapping
   // map lookup function inlined for efficiency
diff --git a/src/atom_vec.cpp b/src/atom_vec.cpp
index 4a00e5852b..6e46406d1b 100644
--- a/src/atom_vec.cpp
+++ b/src/atom_vec.cpp
@@ -2306,12 +2306,12 @@ void AtomVec::write_improper(FILE *fp, int n, tagint **buf, int index)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVec::memory_usage()
+double AtomVec::memory_usage()
 {
   int datatype,cols,maxcols;
   void *pdata;
 
-  bigint bytes = 0;
+  double bytes = 0;
 
   bytes += memory->usage(tag,nmax);
   bytes += memory->usage(type,nmax);
diff --git a/src/atom_vec.h b/src/atom_vec.h
index 07dec63506..5064a1cee7 100644
--- a/src/atom_vec.h
+++ b/src/atom_vec.h
@@ -151,8 +151,8 @@ class AtomVec : protected Pointers {
   virtual int property_atom(char *) {return -1;}
   virtual void pack_property_atom(int, double *, int, int) {}
 
-  virtual bigint memory_usage();
-  virtual bigint memory_usage_bonus() {return 0;}
+  virtual double memory_usage();
+  virtual double memory_usage_bonus() {return 0;}
 
   // old hybrid functions, needed by Kokkos package
 
diff --git a/src/atom_vec_body.cpp b/src/atom_vec_body.cpp
index e9044519c9..78bde4a2e1 100644
--- a/src/atom_vec_body.cpp
+++ b/src/atom_vec_body.cpp
@@ -551,9 +551,9 @@ void AtomVecBody::data_body(int m, int ninteger, int ndouble,
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecBody::memory_usage_bonus()
+double AtomVecBody::memory_usage_bonus()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += nmax_bonus*sizeof(Bonus);
   bytes += icp->size() + dcp->size();
 
diff --git a/src/atom_vec_body.h b/src/atom_vec_body.h
index 809d90c25f..4a4c0d0e60 100644
--- a/src/atom_vec_body.h
+++ b/src/atom_vec_body.h
@@ -56,7 +56,7 @@ class AtomVecBody : public AtomVec {
   int pack_restart_bonus(int, double *);
   int unpack_restart_bonus(int, double *);
   void data_body(int, int, int, int *, double *);
-  bigint memory_usage_bonus();
+  double memory_usage_bonus();
 
   void create_atom_post(int);
   void data_atom_post(int);
diff --git a/src/atom_vec_ellipsoid.cpp b/src/atom_vec_ellipsoid.cpp
index c22111f48c..59f6cb9b0d 100644
--- a/src/atom_vec_ellipsoid.cpp
+++ b/src/atom_vec_ellipsoid.cpp
@@ -414,9 +414,9 @@ void AtomVecEllipsoid::data_atom_bonus(int m, char **values)
    return # of bytes of allocated bonus memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecEllipsoid::memory_usage_bonus()
+double AtomVecEllipsoid::memory_usage_bonus()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += nmax_bonus*sizeof(Bonus);
   return bytes;
 }
diff --git a/src/atom_vec_ellipsoid.h b/src/atom_vec_ellipsoid.h
index 041a20affd..57646522ec 100644
--- a/src/atom_vec_ellipsoid.h
+++ b/src/atom_vec_ellipsoid.h
@@ -49,7 +49,7 @@ class AtomVecEllipsoid : public AtomVec {
   int pack_restart_bonus(int, double *);
   int unpack_restart_bonus(int, double *);
   void data_atom_bonus(int, char **);
-  bigint memory_usage_bonus();
+  double memory_usage_bonus();
 
   void create_atom_post(int);
   void data_atom_post(int);
diff --git a/src/atom_vec_hybrid.cpp b/src/atom_vec_hybrid.cpp
index 7a8c73570d..bc0f804860 100644
--- a/src/atom_vec_hybrid.cpp
+++ b/src/atom_vec_hybrid.cpp
@@ -379,9 +379,9 @@ int AtomVecHybrid::unpack_restart_bonus(int ilocal, double *buf)
 
 /* ---------------------------------------------------------------------- */
 
-bigint AtomVecHybrid::memory_usage_bonus()
+double AtomVecHybrid::memory_usage_bonus()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   for (int k = 0; k < nstyles_bonus; k++)
     bytes += styles_bonus[k]->memory_usage_bonus();
   return bytes;
diff --git a/src/atom_vec_hybrid.h b/src/atom_vec_hybrid.h
index 00be1b0418..2d8d5dec29 100644
--- a/src/atom_vec_hybrid.h
+++ b/src/atom_vec_hybrid.h
@@ -48,7 +48,7 @@ class AtomVecHybrid : public AtomVec {
   int size_restart_bonus();
   int pack_restart_bonus(int, double *);
   int unpack_restart_bonus(int, double *);
-  bigint memory_usage_bonus();
+  double memory_usage_bonus();
 
   void pack_restart_pre(int);
   void pack_restart_post(int);
diff --git a/src/atom_vec_line.cpp b/src/atom_vec_line.cpp
index 88dcb8c2fa..c5beaaee82 100644
--- a/src/atom_vec_line.cpp
+++ b/src/atom_vec_line.cpp
@@ -380,9 +380,9 @@ void AtomVecLine::data_atom_bonus(int m, char **values)
    return # of bytes of allocated bonus memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecLine::memory_usage_bonus()
+double AtomVecLine::memory_usage_bonus()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += nmax_bonus*sizeof(Bonus);
   return bytes;
 }
diff --git a/src/atom_vec_line.h b/src/atom_vec_line.h
index 55a4b8bc02..449d8a1c04 100644
--- a/src/atom_vec_line.h
+++ b/src/atom_vec_line.h
@@ -49,7 +49,7 @@ class AtomVecLine : public AtomVec {
   int pack_restart_bonus(int, double *);
   int unpack_restart_bonus(int, double *);
   void data_atom_bonus(int, char **);
-  bigint memory_usage_bonus();
+  double memory_usage_bonus();
 
   void create_atom_post(int);
   void data_atom_post(int);
diff --git a/src/atom_vec_tri.cpp b/src/atom_vec_tri.cpp
index e391a73215..0394a6c35a 100644
--- a/src/atom_vec_tri.cpp
+++ b/src/atom_vec_tri.cpp
@@ -601,9 +601,9 @@ void AtomVecTri::data_atom_bonus(int m, char **values)
    return # of bytes of allocated bonus memory
 ------------------------------------------------------------------------- */
 
-bigint AtomVecTri::memory_usage_bonus()
+double AtomVecTri::memory_usage_bonus()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += nmax_bonus*sizeof(Bonus);
   return bytes;
 }
diff --git a/src/atom_vec_tri.h b/src/atom_vec_tri.h
index 9becf315f6..06898f20f5 100644
--- a/src/atom_vec_tri.h
+++ b/src/atom_vec_tri.h
@@ -51,7 +51,7 @@ class AtomVecTri : public AtomVec {
   int pack_restart_bonus(int, double *);
   int unpack_restart_bonus(int, double *);
   void data_atom_bonus(int, char **);
-  bigint memory_usage_bonus();
+  double memory_usage_bonus();
 
   void create_atom_post(int);
   void data_atom_post(int);
diff --git a/src/comm.h b/src/comm.h
index 1743436e22..6672891a42 100644
--- a/src/comm.h
+++ b/src/comm.h
@@ -104,7 +104,7 @@ class Comm : protected Pointers {
 
   // memory usage
 
-  virtual bigint memory_usage() = 0;
+  virtual double memory_usage() = 0;
 
   // non-virtual functions common to all Comm styles
 
diff --git a/src/comm_brick.cpp b/src/comm_brick.cpp
index 37a4f0ae3d..769ff8ad93 100644
--- a/src/comm_brick.cpp
+++ b/src/comm_brick.cpp
@@ -1499,9 +1499,9 @@ void *CommBrick::extract(const char *str, int &dim)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint CommBrick::memory_usage()
+double CommBrick::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += nprocs * sizeof(int);    // grid2proc
   for (int i = 0; i < nswap; i++)
     bytes += memory->usage(sendlist[i],maxsendlist[i]);
diff --git a/src/comm_brick.h b/src/comm_brick.h
index 05268da63e..6165f54de5 100644
--- a/src/comm_brick.h
+++ b/src/comm_brick.h
@@ -47,7 +47,7 @@ class CommBrick : public Comm {
   void forward_comm_array(int, double **);         // forward comm of array
   int exchange_variable(int, double *, double *&);  // exchange on neigh stencil
   void *extract(const char *,int &);
-  virtual bigint memory_usage();
+  virtual double memory_usage();
 
  protected:
   int nswap;                        // # of swaps to perform = sum of maxneed
diff --git a/src/comm_tiled.cpp b/src/comm_tiled.cpp
index 48c9680d2f..a78727663f 100644
--- a/src/comm_tiled.cpp
+++ b/src/comm_tiled.cpp
@@ -2249,8 +2249,8 @@ void CommTiled::deallocate_swap(int n)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint CommTiled::memory_usage()
+double CommTiled::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   return bytes;
 }
diff --git a/src/comm_tiled.h b/src/comm_tiled.h
index aa8867b2c3..fa2c76e6e9 100644
--- a/src/comm_tiled.h
+++ b/src/comm_tiled.h
@@ -50,7 +50,7 @@ class CommTiled : public Comm {
   void coord2proc_setup();
   int coord2proc(double *, int &, int &, int &);
 
-  bigint memory_usage();
+  double memory_usage();
 
  private:
   int nswap;                    // # of swaps to perform = 2*dim
diff --git a/src/dump.cpp b/src/dump.cpp
index febc3d0821..b4584ffd64 100644
--- a/src/dump.cpp
+++ b/src/dump.cpp
@@ -1172,9 +1172,9 @@ void Dump::pbc_allocate()
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint Dump::memory_usage()
+double Dump::memory_usage()
 {
-  bigint bytes = memory->usage(buf,size_one*maxbuf);
+  double bytes = memory->usage(buf,size_one*maxbuf);
   bytes += memory->usage(sbuf,maxsbuf);
   if (sort_flag) {
     if (sortcol == 0) bytes += memory->usage(ids,maxids);
diff --git a/src/dump.h b/src/dump.h
index 17e9434faa..fb6627a2b3 100644
--- a/src/dump.h
+++ b/src/dump.h
@@ -47,7 +47,7 @@ class Dump : protected Pointers {
   virtual void unpack_reverse_comm(int, int *, double *) {}
 
   void modify_params(int, char **);
-  virtual bigint memory_usage();
+  virtual double memory_usage();
 
  protected:
   int me,nprocs;             // proc info
diff --git a/src/dump_custom.cpp b/src/dump_custom.cpp
index 167d88789c..66d9d52170 100644
--- a/src/dump_custom.cpp
+++ b/src/dump_custom.cpp
@@ -2091,9 +2091,9 @@ int DumpCustom::modify_param(int narg, char **arg)
    return # of bytes of allocated memory in buf, choose, variable arrays
 ------------------------------------------------------------------------- */
 
-bigint DumpCustom::memory_usage()
+double DumpCustom::memory_usage()
 {
-  bigint bytes = Dump::memory_usage();
+  double bytes = Dump::memory_usage();
   bytes += memory->usage(choose,maxlocal);
   bytes += memory->usage(dchoose,maxlocal);
   bytes += memory->usage(clist,maxlocal);
diff --git a/src/dump_custom.h b/src/dump_custom.h
index 0f63eac8de..654a87fc6a 100644
--- a/src/dump_custom.h
+++ b/src/dump_custom.h
@@ -102,7 +102,7 @@ class DumpCustom : public Dump {
   void pack(tagint *);
   virtual int convert_string(int, double *);
   virtual void write_data(int, double *);
-  bigint memory_usage();
+  double memory_usage();
 
   int parse_fields(int, char **);
   int add_compute(char *);
diff --git a/src/dump_dcd.cpp b/src/dump_dcd.cpp
index 254b371e22..bb73d8975b 100644
--- a/src/dump_dcd.cpp
+++ b/src/dump_dcd.cpp
@@ -263,9 +263,9 @@ int DumpDCD::modify_param(int narg, char **arg)
    return # of bytes of allocated memory in buf and global coords array
 ------------------------------------------------------------------------- */
 
-bigint DumpDCD::memory_usage()
+double DumpDCD::memory_usage()
 {
-  bigint bytes = Dump::memory_usage();
+  double bytes = Dump::memory_usage();
   bytes += memory->usage(coords,natoms*3);
   return bytes;
 }
diff --git a/src/dump_dcd.h b/src/dump_dcd.h
index 15f6faf4be..3f59490b11 100644
--- a/src/dump_dcd.h
+++ b/src/dump_dcd.h
@@ -42,7 +42,7 @@ class DumpDCD : public Dump {
   void pack(tagint *);
   void write_data(int, double *);
   int modify_param(int, char **);
-  bigint memory_usage();
+  double memory_usage();
 
   void write_frame();
   void write_dcd_header(const char *);
diff --git a/src/fix_numdiff.cpp b/src/fix_numdiff.cpp
index 145d60e8df..085b9215dd 100644
--- a/src/fix_numdiff.cpp
+++ b/src/fix_numdiff.cpp
@@ -338,7 +338,7 @@ void FixNumDiff::reallocate()
 
 double FixNumDiff::memory_usage()
 {
-  bigint bytes = 0.0;
+  double bytes = 0.0;
   bytes += 3 * maxatom*3 * sizeof(double);
   return bytes;
 }
diff --git a/src/force.cpp b/src/force.cpp
index 701113d7ef..11c21df752 100644
--- a/src/force.cpp
+++ b/src/force.cpp
@@ -836,9 +836,9 @@ void Force::set_special(int narg, char **arg)
    memory usage of force classes
 ------------------------------------------------------------------------- */
 
-bigint Force::memory_usage()
+double Force::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   if (pair) bytes += static_cast<bigint> (pair->memory_usage());
   if (bond) bytes += static_cast<bigint> (bond->memory_usage());
   if (angle) bytes += static_cast<bigint> (angle->memory_usage());
diff --git a/src/force.h b/src/force.h
index 1302e20f12..a2cc37f0b8 100644
--- a/src/force.h
+++ b/src/force.h
@@ -135,7 +135,7 @@ class Force : protected Pointers {
   void store_style(char *&, const std::string &, int);
   void set_special(int, char **);
 
-  bigint memory_usage();
+  double memory_usage();
 
  private:
   void create_factories();
diff --git a/src/info.cpp b/src/info.cpp
index 87161e9ca5..ccf6eb4145 100644
--- a/src/info.cpp
+++ b/src/info.cpp
@@ -315,41 +315,23 @@ void Info::command(int narg, char **arg)
   }
 
   if (flags & MEMORY) {
+    double meminfo[3];
+
+    get_memory_info(meminfo);
 
     fputs("\nMemory allocation information (MPI rank 0):\n\n",out);
-
-    bigint bytes = 0;
-    bytes += atom->memory_usage();
-    bytes += neighbor->memory_usage();
-    bytes += comm->memory_usage();
-    bytes += update->memory_usage();
-    bytes += force->memory_usage();
-    bytes += modify->memory_usage();
-    for (int i = 0; i < output->ndump; i++)
-      bytes += output->dump[i]->memory_usage();
-    double mbytes = bytes/1024.0/1024.0;
-    fmt::print(out,"Total dynamically allocated memory: {:.4} Mbyte\n",mbytes);
+    fmt::print(out,"Total dynamically allocated memory: {:.4} Mbyte\n",
+               meminfo[0]);
 
 #if defined(_WIN32)
-    HANDLE phandle = GetCurrentProcess();
-    PROCESS_MEMORY_COUNTERS_EX pmc;
-    GetProcessMemoryInfo(phandle,(PROCESS_MEMORY_COUNTERS *)&pmc,sizeof(pmc));
-    fmt::print(out,"Non-shared memory use: {:.4} Mbyte\n",
-               (double)pmc.PrivateUsage/1048576.0);
-    fmt::print(out,"Maximum working set size: {:.4} Mbyte\n",
-               (double)pmc.PeakWorkingSetSize/1048576.0);
+    fmt::print(out,"Non-shared memory use: {:.4} Mbyte\n",meminfo[1]);
+    fmt::print(out,"Maximum working set size: {:.4} Mbyte\n",meminfo[2]);
 #else
 #if defined(__linux__)
-    struct mallinfo mi;
-    mi = mallinfo();
     fmt::print(out,"Current reserved memory pool size: {:.4} Mbyte\n",
-               (double)mi.uordblks/1048576.0+(double)mi.hblkhd/1048576.0);
+               meminfo[1]);
 #endif
-    struct rusage ru;
-    if (getrusage(RUSAGE_SELF, &ru) == 0) {
-      fmt::print(out,"Maximum resident set size: {:.4} Mbyte\n",
-                 (double)ru.ru_maxrss/1024.0);
-    }
+    fmt::print(out,"Maximum resident set size: {:.4} Mbyte\n",meminfo[2]);
 #endif
   }
 
@@ -1300,6 +1282,41 @@ std::string Info::get_cxx_info()
 
 /* ---------------------------------------------------------------------- */
 
+void Info::get_memory_info(double *meminfo)
+{
+    double bytes = 0;
+    bytes += atom->memory_usage();
+    bytes += neighbor->memory_usage();
+    bytes += comm->memory_usage();
+    bytes += update->memory_usage();
+    bytes += force->memory_usage();
+    bytes += modify->memory_usage();
+    for (int i = 0; i < output->ndump; i++)
+      bytes += output->dump[i]->memory_usage();
+    meminfo[0] = bytes/1024.0/1024.0;
+    meminfo[1] = 0;
+    meminfo[2] = 0;
+
+#if defined(_WIN32)
+    HANDLE phandle = GetCurrentProcess();
+    PROCESS_MEMORY_COUNTERS_EX pmc;
+    GetProcessMemoryInfo(phandle,(PROCESS_MEMORY_COUNTERS *)&pmc,sizeof(pmc));
+    meminfo[1] = (double)pmc.PrivateUsage/1048576.0;
+    meminfo[2] = (double)pmc.PeakWorkingSetSize/1048576.0;
+#else
+#if defined(__linux__)
+    struct mallinfo mi;
+    mi = mallinfo();
+    meminfo[1] = (double)mi.uordblks/1048576.0+(double)mi.hblkhd/1048576.0;
+#endif
+    struct rusage ru;
+    if (getrusage(RUSAGE_SELF, &ru) == 0)
+      meminfo[2] = (double)ru.ru_maxrss/1024.0;
+#endif
+}
+
+/* ---------------------------------------------------------------------- */
+
 char **Info::get_variable_names(int &num) {
     num = input->variable->nvar;
     return input->variable->names;
diff --git a/src/info.h b/src/info.h
index 65690ab28e..ae61600b68 100644
--- a/src/info.h
+++ b/src/info.h
@@ -52,6 +52,7 @@ class Info : protected Pointers {
   static std::string get_mpi_info(int &, int &);
   static std::string get_cxx_info();
 
+  void get_memory_info(double *);
   char **get_variable_names(int &num);
 
 private:
diff --git a/src/integrate.h b/src/integrate.h
index f07faacbfa..c9aa92e097 100644
--- a/src/integrate.h
+++ b/src/integrate.h
@@ -28,7 +28,7 @@ class Integrate : protected Pointers {
   virtual void run(int) = 0;
   virtual void cleanup() {}
   virtual void reset_dt() {}
-  virtual bigint memory_usage() {return 0;}
+  virtual double memory_usage() {return 0;}
 
  protected:
   int eflag,vflag;                  // flags for energy/virial computation
diff --git a/src/irregular.cpp b/src/irregular.cpp
index fbb572fd88..47ee864abc 100644
--- a/src/irregular.cpp
+++ b/src/irregular.cpp
@@ -1051,9 +1051,9 @@ void Irregular::grow_recv(int n)
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint Irregular::memory_usage()
+double Irregular::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += maxsend*sizeof(double);   // buf_send
   bytes += maxrecv*sizeof(double);   // buf_recv
   bytes += maxdbuf*sizeof(double);   // dbuf
diff --git a/src/irregular.h b/src/irregular.h
index 01fe40c46b..9af6e52557 100644
--- a/src/irregular.h
+++ b/src/irregular.h
@@ -36,7 +36,7 @@ class Irregular : protected Pointers {
   int create_data_grouped(int, int *, int sortflag = 0);
   void exchange_data(char *, int, char *);
   void destroy_data();
-  bigint memory_usage();
+  double memory_usage();
 
  private:
   int me,nprocs;
diff --git a/src/library.cpp b/src/library.cpp
index 7abc0df38a..6ebda8e616 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -532,6 +532,38 @@ int lammps_version(void *handle)
   return atoi(lmp->universe->num_ver);
 }
 
+/* ---------------------------------------------------------------------- */
+
+/** Get memory usage information
+ *
+\verbatim embed:rst
+
+This function will retrieve memory usage information for the current
+LAMMPS instance or process.  The *meminfo* buffer will be filled with
+3 different numbers (if supported by the operating system).  The first
+is the tally (in MBytes) of all large memory allocations made by LAMMPS.
+This is a lower boundary of how much memory is requested and does not
+account for memory allocated on the stack or allocations via ``new``.
+The second number is the current memory allocation of the current process
+as returned by a memory allocation reporting in the system library.  The
+third number is the maximum amount of RAM (not swap) used by the process
+so far. If any of the two latter parameters is not supported by the operating
+system it will be set to zero.
+
+.. versionadded:: 15Sep2020
+
+\endverbatim
+ *
+ * \param  handle   pointer to a previously created LAMMPS instance
+ * \param  meminfo  buffer with space for at least 3 double to store
+ * data in. */
+
+void lammps_memory_usage(void *handle, double *meminfo)
+{
+  LAMMPS *lmp = (LAMMPS *) handle;
+  Info info(lmp);
+  info.get_memory_info(meminfo);
+}
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/library.h b/src/library.h
index 0c6ca184e5..4cf2dd6d19 100644
--- a/src/library.h
+++ b/src/library.h
@@ -98,7 +98,8 @@ void  lammps_commands_string(void *handle, const char *str);
  * ----------------------------------------------------------------------- */
 
 int    lammps_version(void *handle);
-int    lammps_get_mpi_comm(void* handle);
+void   lammps_memory_usage(void *handle, double *meminfo);
+int    lammps_get_mpi_comm(void *handle);
 double lammps_get_natoms(void *handle);
 double lammps_get_thermo(void *handle, const char *keyword);
 
diff --git a/src/memory.h b/src/memory.h
index 42c9bf6aba..ef55dc2c87 100644
--- a/src/memory.h
+++ b/src/memory.h
@@ -617,40 +617,40 @@ class Memory : protected Pointers {
 ------------------------------------------------------------------------- */
 
   template <typename TYPE>
-  bigint usage(TYPE *array, int n)
+  double usage(TYPE *array, int n)
   {
     (void) array;
-    bigint bytes = ((bigint) sizeof(TYPE)) * n;
+    double bytes = ((double) sizeof(TYPE)) * n;
     return bytes;
   }
 
   template <typename TYPE>
-  bigint usage(TYPE **array, int n1, int n2)
+  double usage(TYPE **array, int n1, int n2)
   {
     (void) array;
-    bigint bytes = ((bigint) sizeof(TYPE)) * n1*n2;
-    bytes += ((bigint) sizeof(TYPE *)) * n1;
+    double bytes = ((double) sizeof(TYPE)) * n1*n2;
+    bytes += ((double) sizeof(TYPE *)) * n1;
     return bytes;
   }
 
   template <typename TYPE>
-  bigint usage(TYPE ***array, int n1, int n2, int n3)
+  double usage(TYPE ***array, int n1, int n2, int n3)
   {
     (void) array;
-    bigint bytes = ((bigint) sizeof(TYPE)) * n1*n2*n3;
-    bytes += ((bigint) sizeof(TYPE *)) * n1*n2;
-    bytes += ((bigint) sizeof(TYPE **)) * n1;
+    double bytes = ((double) sizeof(TYPE)) * n1*n2*n3;
+    bytes += ((double) sizeof(TYPE *)) * n1*n2;
+    bytes += ((double) sizeof(TYPE **)) * n1;
     return bytes;
   }
 
   template <typename TYPE>
-  bigint usage(TYPE ****array, int n1, int n2, int n3, int n4)
+  double usage(TYPE ****array, int n1, int n2, int n3, int n4)
   {
     (void) array;
-    bigint bytes = ((bigint) sizeof(TYPE)) * n1*n2*n3*n4;
-    bytes += ((bigint) sizeof(TYPE *)) * n1*n2*n3;
-    bytes += ((bigint) sizeof(TYPE **)) * n1*n2;
-    bytes += ((bigint) sizeof(TYPE ***)) * n1;
+    double bytes = ((double) sizeof(TYPE)) * n1*n2*n3*n4;
+    bytes += ((double) sizeof(TYPE *)) * n1*n2*n3;
+    bytes += ((double) sizeof(TYPE **)) * n1*n2;
+    bytes += ((double) sizeof(TYPE ***)) * n1;
     return bytes;
   }
 };
diff --git a/src/min.h b/src/min.h
index 1db196a55e..438a775d16 100644
--- a/src/min.h
+++ b/src/min.h
@@ -36,7 +36,7 @@ class Min : protected Pointers {
   virtual void run(int);
   void cleanup();
   int request(class Pair *, int, double);
-  virtual bigint memory_usage() {return 0;}
+  virtual double memory_usage() {return 0;}
   void modify_params(int, char **);
   virtual int modify_param(int, char **) {return 0;}
   virtual double fnorm_sqr();
diff --git a/src/modify.cpp b/src/modify.cpp
index c88d52b623..9d0511ca6f 100644
--- a/src/modify.cpp
+++ b/src/modify.cpp
@@ -1676,9 +1676,9 @@ void Modify::list_init_compute()
    return # of bytes of allocated memory from all fixes
 ------------------------------------------------------------------------- */
 
-bigint Modify::memory_usage()
+double Modify::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   for (int i = 0; i < nfix; i++)
     bytes += static_cast<bigint> (fix[i]->memory_usage());
   for (int i = 0; i < ncompute; i++)
diff --git a/src/modify.h b/src/modify.h
index 4c3db0a1b9..ee14baf638 100644
--- a/src/modify.h
+++ b/src/modify.h
@@ -125,7 +125,7 @@ class Modify : protected Pointers {
   int read_restart(FILE *);
   void restart_deallocate(int);
 
-  bigint memory_usage();
+  double memory_usage();
 
  protected:
 
diff --git a/src/nbin.cpp b/src/nbin.cpp
index 1092311f6a..66c5bd4159 100644
--- a/src/nbin.cpp
+++ b/src/nbin.cpp
@@ -153,9 +153,9 @@ int NBin::coord2bin(double *x)
 
 /* ---------------------------------------------------------------------- */
 
-bigint NBin::memory_usage()
+double NBin::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += maxbin*sizeof(int);
   bytes += 2*maxatom*sizeof(int);
   return bytes;
diff --git a/src/nbin.h b/src/nbin.h
index 54b8da171d..4bfe579514 100644
--- a/src/nbin.h
+++ b/src/nbin.h
@@ -42,7 +42,7 @@ class NBin : protected Pointers {
   void post_constructor(class NeighRequest *);
   virtual void copy_neighbor_info();
   virtual void bin_atoms_setup(int);
-  bigint memory_usage();
+  double memory_usage();
 
   virtual void setup_bins(int) = 0;
   virtual void bin_atoms() = 0;
diff --git a/src/neigh_list.cpp b/src/neigh_list.cpp
index c01f8ca595..8798ec8f99 100644
--- a/src/neigh_list.cpp
+++ b/src/neigh_list.cpp
@@ -294,9 +294,9 @@ void NeighList::print_attributes()
    if stencilflag = 0, maxstencil * maxstencil_multi will also be 0
 ------------------------------------------------------------------------- */
 
-bigint NeighList::memory_usage()
+double NeighList::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += memory->usage(ilist,maxatom);
   bytes += memory->usage(numneigh,maxatom);
   bytes += maxatom * sizeof(int *);
diff --git a/src/neigh_list.h b/src/neigh_list.h
index c26b008136..d69b844dc8 100644
--- a/src/neigh_list.h
+++ b/src/neigh_list.h
@@ -107,7 +107,7 @@ class NeighList : protected Pointers {
   void grow(int,int);                   // grow all data structs
   void print_attributes();              // debug routine
   int get_maxlocal() {return maxatom;}
-  bigint memory_usage();
+  double memory_usage();
 };
 
 }
diff --git a/src/neighbor.cpp b/src/neighbor.cpp
index 66ab92496a..4fc54aafc2 100644
--- a/src/neighbor.cpp
+++ b/src/neighbor.cpp
@@ -2390,9 +2390,9 @@ int Neighbor::exclude_setting()
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
 
-bigint Neighbor::memory_usage()
+double Neighbor::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += memory->usage(xhold,maxhold,3);
 
   for (int i = 0; i < nlist; i++)
diff --git a/src/neighbor.h b/src/neighbor.h
index 8fe423c60c..9ee2af9c75 100644
--- a/src/neighbor.h
+++ b/src/neighbor.h
@@ -123,7 +123,7 @@ class Neighbor : protected Pointers {
   int exclude_setting();            // return exclude value to accelerator pkg
   class NeighRequest *find_request(void *);  // find a neighbor request
 
-  bigint memory_usage();
+  double memory_usage();
 
   bigint last_setup_bins;          // step of last neighbor::setup_bins() call
 
diff --git a/src/nstencil.cpp b/src/nstencil.cpp
index 431906e898..9eb1818b83 100644
--- a/src/nstencil.cpp
+++ b/src/nstencil.cpp
@@ -222,9 +222,9 @@ double NStencil::bin_distance(int i, int j, int k)
 
 /* ---------------------------------------------------------------------- */
 
-bigint NStencil::memory_usage()
+double NStencil::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   if (neighstyle == Neighbor::BIN) {
     bytes += memory->usage(stencil,maxstencil);
     bytes += memory->usage(stencilxyz,maxstencil,3);
diff --git a/src/nstencil.h b/src/nstencil.h
index a4c6a4af66..75e678b483 100644
--- a/src/nstencil.h
+++ b/src/nstencil.h
@@ -39,7 +39,7 @@ class NStencil : protected Pointers {
   void post_constructor(class NeighRequest *);
   void copy_neighbor_info();
   virtual void create_setup();
-  bigint memory_usage();
+  double memory_usage();
 
   virtual void create() = 0;
 
diff --git a/src/ntopo.cpp b/src/ntopo.cpp
index d4ddcc7fc0..a53d88505b 100644
--- a/src/ntopo.cpp
+++ b/src/ntopo.cpp
@@ -206,9 +206,9 @@ void NTopo::dihedral_check(int nlist, int **list)
 
 /* ---------------------------------------------------------------------- */
 
-bigint NTopo::memory_usage()
+double NTopo::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   bytes += 3*maxbond * sizeof(int);
   bytes += 4*maxangle * sizeof(int);
   bytes += 5*maxdihedral * sizeof(int);
diff --git a/src/ntopo.h b/src/ntopo.h
index b115b32965..3e4204cead 100644
--- a/src/ntopo.h
+++ b/src/ntopo.h
@@ -28,7 +28,7 @@ class NTopo : protected Pointers {
 
   virtual void build() = 0;
 
-  bigint memory_usage();
+  double memory_usage();
 
  protected:
   int me,nprocs;
diff --git a/src/output.cpp b/src/output.cpp
index 6c90198de4..d4fd5ae75e 100644
--- a/src/output.cpp
+++ b/src/output.cpp
@@ -21,6 +21,7 @@
 #include "error.h"
 #include "force.h"
 #include "group.h"
+#include "info.h"
 #include "input.h"
 #include "memory.h"
 #include "modify.h"
@@ -817,28 +818,19 @@ void Output::create_restart(int narg, char **arg)
 
 void Output::memory_usage()
 {
-  bigint bytes = 0;
-  bytes += atom->memory_usage();
-  bytes += neighbor->memory_usage();
-  bytes += comm->memory_usage();
-  bytes += update->memory_usage();
-  bytes += force->memory_usage();
-  bytes += modify->memory_usage();
-  for (int i = 0; i < ndump; i++) bytes += dump[i]->memory_usage();
+  double meminfo[3];
+  Info info(lmp);
 
-  double mbytes = bytes/1024.0/1024.0;
-  double mbavg,mbmin,mbmax;
+  info.get_memory_info(meminfo);
+  double mbytes = meminfo[0];
+  double mbmin,mbavg,mbmax;
   MPI_Reduce(&mbytes,&mbavg,1,MPI_DOUBLE,MPI_SUM,0,world);
   MPI_Reduce(&mbytes,&mbmin,1,MPI_DOUBLE,MPI_MIN,0,world);
   MPI_Reduce(&mbytes,&mbmax,1,MPI_DOUBLE,MPI_MAX,0,world);
+  mbavg /= comm->nprocs;
 
-  if (comm->me == 0) {
-    mbavg /= comm->nprocs;
-    if (screen)
-      fprintf(screen,"Per MPI rank memory allocation (min/avg/max) = "
-              "%.4g | %.4g | %.4g Mbytes\n",mbmin,mbavg,mbmax);
-    if (logfile)
-      fprintf(logfile,"Per MPI rank memory allocation (min/avg/max) = "
-              "%.4g | %.4g | %.4g Mbytes\n",mbmin,mbavg,mbmax);
-  }
+  if (comm->me == 0)
+    utils::logmesg(lmp,fmt::format("Per MPI rank memory allocation (min/avg/"
+                                   "max) = {:.4} | {:.4} | {:.4} Mbytes\n",
+                                   mbmin,mbavg,mbmax));
 }
diff --git a/src/rcb.cpp b/src/rcb.cpp
index 03c99560b3..9cb4248ab0 100644
--- a/src/rcb.cpp
+++ b/src/rcb.cpp
@@ -1261,9 +1261,9 @@ void RCB::invert(int sortflag)
    memory use of Irregular
 ------------------------------------------------------------------------- */
 
-bigint RCB::memory_usage()
+double RCB::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   if (irregular) bytes += irregular->memory_usage();
   return bytes;
 }
diff --git a/src/rcb.h b/src/rcb.h
index 555c4142b5..a3dc37bb9b 100644
--- a/src/rcb.h
+++ b/src/rcb.h
@@ -43,7 +43,7 @@ class RCB : protected Pointers {
   void compute(int, int, double **, double *, double *, double *);
   void compute_old(int, int, double **, double *, double *, double *);
   void invert(int sortflag = 0);
-  bigint memory_usage();
+  double memory_usage();
 
   // DEBUG methods
   //void check();
diff --git a/src/update.cpp b/src/update.cpp
index d591e05131..f6ed47dcd2 100644
--- a/src/update.cpp
+++ b/src/update.cpp
@@ -537,9 +537,9 @@ void Update::update_time()
    memory usage of update and integrate/minimize
 ------------------------------------------------------------------------- */
 
-bigint Update::memory_usage()
+double Update::memory_usage()
 {
-  bigint bytes = 0;
+  double bytes = 0;
   if (whichflag == 1) bytes += integrate->memory_usage();
   else if (whichflag == 2) bytes += minimize->memory_usage();
   return bytes;
diff --git a/src/update.h b/src/update.h
index 1d1e04b8bd..f2a28619fb 100644
--- a/src/update.h
+++ b/src/update.h
@@ -68,7 +68,7 @@ class Update : protected Pointers {
   void reset_timestep(int, char **);
   void reset_timestep(bigint);
   void update_time();
-  bigint memory_usage();
+  double memory_usage();
 
  private:
   void new_integrate(char *, int, char **, int, int &);
diff --git a/unittest/c-library/test_library_properties.cpp b/unittest/c-library/test_library_properties.cpp
index 3b1393e5c6..5db779521b 100644
--- a/unittest/c-library/test_library_properties.cpp
+++ b/unittest/c-library/test_library_properties.cpp
@@ -54,6 +54,17 @@ TEST_F(LibraryProperties, version)
     EXPECT_GE(20200824, lammps_version(lmp));
 };
 
+TEST_F(LibraryProperties, memory_usage)
+{
+    double meminfo[3];
+    lammps_memory_usage(lmp,meminfo);
+    EXPECT_GT(meminfo[0], 0.0);
+#if defined(__linux__) || defined(_WIN32)
+    EXPECT_GT(meminfo[1], 0.0);
+#endif
+    EXPECT_GT(meminfo[2], 0.0);
+};
+
 TEST_F(LibraryProperties, get_mpi_comm)
 {
     int f_comm = lammps_get_mpi_comm(lmp);