Before man invented rulers and tae measures he often used his hands and feet to express the size of things. An old book published in 1561 says: “Fouregraines of barley make a finger; foure finger a hande; foure hands a Foote”.
Today horses are still measured in hands. The measurement is taken from the ground to the withers, which is the highest part of the back lying between the shoulder blades.
A hand is reckoned to be four inches, the assumed width of a man’ palm. Formerly it was taken as equal to three inches, when a man’s hand was smaller.
Early horses were probably around 12 hands (48 inches) at the withers, and one measuring 14 hands was exceptional. Some modern horses, however reach 17 hands and occasionally 20 had. A small horse under 14.2 hands is called a pony.