diff --git a/doc/src/dump.rst b/doc/src/dump.rst
index 40eafbb427..6fce1fcaa6 100644
--- a/doc/src/dump.rst
+++ b/doc/src/dump.rst
@@ -363,22 +363,32 @@ attributes is given below.
 
 .. versionadded:: 22Dec2022
 
-For style *grid* the extent of the Nx by Ny by Nz grid that overlays
-the simulation domain is output with each snapshot:
+For style *grid* the dimension of the simulation domain and size of
+the Nx by Ny by Nz grid that overlays the simulation domain are also
+output with each snapshot:
 
 .. parsed-literal::
 
-   ITEM: GRID EXTENT
+   ITEM: DIMENSION
+   dim
+   ITEM: GRID SIZE
    nx ny nz
 
-For 2d simulations, nz will be 1.  There will also be an "ITEM: GRID
-DATA" line which includes column descriptors for the per grid cell
-data.  Each subsequent line (Nx * Ny * Nz lines) will list the data
-for a single grid cell.  If grid cell IDs are included in the output
-via the :doc:`compute property/grid <compute_property_grid>` command,
-then the IDs will range from 1 to N = Nx*Ny*Nz.  The ordering of IDs
-is with the x index varying fastest, then the y index, and the z index
-varying slowest.
+The value dim will be 2 or 3 for 2d or 3d simulations.  It is included
+so that post-processing tools like `OVITO <https://www.ovito.org>`,
+which can visualize grid-based quantities know how to draw each grid
+cell.  The grid size will match the input script parameters for
+grid(s) created by the computes or fixes which are referenced by the
+the dump command.  For 2d simulations (and grids), nz will always
+be 1.
+
+There will also be an "ITEM: GRID DATA" line which includes column
+descriptors for the per grid cell data.  Each subsequent line (Nx *
+Ny * Nz lines) will list the data for a single grid cell.  If grid
+cell IDs are included in the output via the :doc:`compute
+property/grid <compute_property_grid>` command, then the IDs will
+range from 1 to N = Nx*Ny*Nz.  The ordering of IDs is with the x index
+varying fastest, then the y index, and the z index varying slowest.
 
 For style *local*, local output generated by :doc:`computes <compute>`
 and :doc:`fixes <fix>` is used to generate lines of output that is
diff --git a/src/dump_grid.cpp b/src/dump_grid.cpp
index 996c7f1301..2ca4f6c5d4 100644
--- a/src/dump_grid.cpp
+++ b/src/dump_grid.cpp
@@ -377,6 +377,7 @@ void DumpGrid::header_binary(bigint ndump)
   fwrite(&boxyhi,sizeof(double),1,fp);
   fwrite(&boxzlo,sizeof(double),1,fp);
   fwrite(&boxzhi,sizeof(double),1,fp);
+  fwrite(&domain->dimension,sizeof(int),1,fp);
   fwrite(&nxgrid,sizeof(int),1,fp);
   fwrite(&nygrid,sizeof(int),1,fp);
   fwrite(&nzgrid,sizeof(int),1,fp);
@@ -409,6 +410,7 @@ void DumpGrid::header_binary_triclinic(bigint ndump)
   fwrite(&boxxy,sizeof(double),1,fp);
   fwrite(&boxxz,sizeof(double),1,fp);
   fwrite(&boxyz,sizeof(double),1,fp);
+  fwrite(&domain->dimension,sizeof(int),1,fp);
   fwrite(&nxgrid,sizeof(int),1,fp);
   fwrite(&nygrid,sizeof(int),1,fp);
   fwrite(&nzgrid,sizeof(int),1,fp);
@@ -438,6 +440,7 @@ void DumpGrid::header_item(bigint /*ndump*/)
              "{:>1.16e} {:>1.16e}\n"
              "{:>1.16e} {:>1.16e}\n",
              boundstr,boxxlo,boxxhi,boxylo,boxyhi,boxzlo,boxzhi);
+  fmt::print(fp,"ITEM: DIMENSION\n{}\n",domain->dimension);
   fmt::print(fp,"ITEM: GRID SIZE nx ny nz\n{} {} {}\n",nxgrid,nygrid,nzgrid);
   fmt::print(fp,"ITEM: GRID CELLS {}\n",columns);
 }
@@ -458,6 +461,7 @@ void DumpGrid::header_item_triclinic(bigint /*ndump*/)
              "{:>1.16e} {:>1.16e} {:>1.16e}\n"
              "{:>1.16e} {:>1.16e} {:>1.16e}\n",
              boundstr,boxxlo,boxxhi,boxxy,boxylo,boxyhi,boxxz,boxzlo,boxzhi,boxyz);
+  fmt::print(fp,"ITEM: DIMENSION\n{}\n",domain->dimension);
   fmt::print(fp,"ITEM: GRID SIZE nx ny nz\n{} {} {}\n",nxgrid,nygrid,nzgrid);
   fmt::print(fp,"ITEM: GRID CELLS {}\n",columns);
 }