Hand

The hand (symbol h or hh) is a traditional non-SI unit of length equal to 4 inches, or exactly 10.16 centimetres. Originating in ancient Egypt and standardized in England by Royal Statute in 1542, it was established to standardize livestock measurements. Today, the hand is exclusively used to measure the height of horses and ponies from the ground to the top of the withstands or withers, recorded in hands and remaining fractional inches.