A hand is the unit of measuring the height of a horse. It’s a standard measurement used throughout the world and is exactly four inches. So a horse forty inches high would be ten hands, or to use its shorthand, 10.0hh.
If the horse is forty-two inches tall, it would be 10.2hh. This measurement is taken from the ground to the whithers, which are the highest point of the horse when its head is down. (A slight rise in front of where the saddle fits).
Do note that miniature ponies are measured in inches, not hands and written as 32″ high.
