diff --git a/dgl/Geometry.hpp b/dgl/Geometry.hpp
index 76d9c158..1f6433b0 100644
--- a/dgl/Geometry.hpp
+++ b/dgl/Geometry.hpp
@@ -219,6 +219,8 @@ public:
     Size<T>& operator-=(const Size<T>& size) noexcept;
     Size<T>& operator*=(double m) noexcept;
     Size<T>& operator/=(double d) noexcept;
+    Size<T> operator*(double m) const noexcept;
+    Size<T> operator/(double m) const noexcept;
     bool operator==(const Size<T>& size) const noexcept;
     bool operator!=(const Size<T>& size) const noexcept;
 
diff --git a/dgl/src/Geometry.cpp b/dgl/src/Geometry.cpp
index 926814ba..dafa7089 100644
--- a/dgl/src/Geometry.cpp
+++ b/dgl/src/Geometry.cpp
@@ -324,6 +324,22 @@ Size<T>& Size<T>::operator/=(double d) noexcept
     return *this;
 }
 
+template<typename T>
+Size<T> Size<T>::operator*(const double m) const noexcept
+{
+    Size<T> size(fWidth, fHeight);
+    size *= m;
+    return size;
+}
+
+template<typename T>
+Size<T> Size<T>::operator/(const double m) const noexcept
+{
+    Size<T> size(fWidth, fHeight);
+    size /= m;
+    return size;
+}
+
 template<typename T>
 bool Size<T>::operator==(const Size<T>& size) const noexcept
 {