What was the approximate body weight of the person or pet you are purchasing the cremation urn for.
1 pound of body weight = 1 cubic inch ash.
Cremation Urns are listed in cubic inches. Approx. Weight=Approx. Size.
Example: A cremated 100 pound person will yield approximately 100 cubic inches of ashes. So, if 1 pound=1 cubic inch then this person would need an urn that is about 100 cubic inches.
Small or medium urns can be used for children or pets.
Large urns are generally used for adults.
It's a good idea to order an urn a little larger than needed.