The conventions of dealing mainly in centimeters and meters when discussing dimensions of human scale items could use fixing.
A simple solution is to promulgate the use of the "metric hand" (or just "hand" for short). 1 hand = 1 decimeter = 10 centimeters; about the width of a human hand. The decimeter has the nice property that it's approximately 4 inches, so there are roughly 3 hands in a foot—similar conversion conversion factor as going from feet to yards. Nice! Error accumulates at only 1.6mm (exactly 1.6mm) per hand.
(Equestrian sports already has a "hand" unit. Conveniently, it's defined as 4 inches, and its use is pretty much confined to those circles. There's not much need to distinguish between the two, therefore, but if ever a need arises, we can clarify whether we're talking about "metric hands" or "horse hands".)