diff --git a/src/lagrangian/intermediate/parcels/Templates/InteractingKinematicParcel/InteractingKinematicParcel.H b/src/lagrangian/intermediate/parcels/Templates/InteractingKinematicParcel/InteractingKinematicParcel.H
index 48ae97ed79..78792ab6e5 100644
--- a/src/lagrangian/intermediate/parcels/Templates/InteractingKinematicParcel/InteractingKinematicParcel.H
+++ b/src/lagrangian/intermediate/parcels/Templates/InteractingKinematicParcel/InteractingKinematicParcel.H
@@ -438,6 +438,9 @@ public:
             //- Particle angular velocity
             inline vector omega() const;
 
+            //- Particle radius
+            inline scalar r() const;
+
             //- Particle volume
             inline scalar volume() const;
 
diff --git a/src/lagrangian/intermediate/parcels/Templates/InteractingKinematicParcel/InteractingKinematicParcelI.H b/src/lagrangian/intermediate/parcels/Templates/InteractingKinematicParcel/InteractingKinematicParcelI.H
index ee2df1df80..ce9693f877 100644
--- a/src/lagrangian/intermediate/parcels/Templates/InteractingKinematicParcel/InteractingKinematicParcelI.H
+++ b/src/lagrangian/intermediate/parcels/Templates/InteractingKinematicParcel/InteractingKinematicParcelI.H
@@ -445,6 +445,13 @@ Foam::InteractingKinematicParcel<ParcelType>::omega() const
 }
 
 
+template <class ParcelType>
+inline Foam::scalar Foam::InteractingKinematicParcel<ParcelType>::r() const
+{
+    return 0.5*d_;
+}
+
+
 template <class ParcelType>
 inline Foam::scalar Foam::InteractingKinematicParcel<ParcelType>::volume() const
 {