The Purr-celain's 13cm outer diameter describes its external footprint, while the 10cm inner diameter describes the bowl opening. Use the outer number to plan where the bowl sits and the inner number to compare the available food area. Neither number replaces the listed 11.5cm overall height.
Use 13cm for the physical footprint
The outer diameter is the more relevant starting point for a shelf, tray or feeding nook. It helps you mark the bowl's widest circular outline, but you should still allow comfortable space to place and lift the glazed ceramic piece without knocking nearby objects.
Use 10cm for the opening
The inner diameter describes the opening across the bowl. Compare it with a familiar bowl and the portions you actually serve. It does not give the internal depth or capacity, which are not stated in the current listing.
Do not calculate missing measurements
The 3cm difference between the two diameters is spread around the circle; it should not be treated as a confirmed rim thickness because the cat-ear shape and fluted construction can change the outline. Do not infer capacity from diameter and height alone.
Trace both circles if space is tight
Draw a 13cm circle to represent the outside footprint and a 10cm circle inside it to represent the listed opening. This paper model is a comparison aid, not proof of fit or stability. Keep it level and add hand clearance around the outside.
Compare bowls on the same basis
When another product gives only one diameter, find out whether it is internal or external before comparing the numbers. The guide to measuring the inside rather than only the cat bowl rim provides the general method.
For another product-specific measurement distinction, read why the Kitty Buffet’s overall height does not state its bowl-rim height.
