How Tall
Horses and Ponies are measured in units called 'hands.' One hand is the equivalent of four inches or ten centimeters.
Height is referred to in hands and inches, so a pony that is 12.2 hh (hands high) is twelve hands and two inches high. Generally, equids up to 14.2 hh are considered to be ponies, and over 14.2 hh they are considered to be horses.
There is now a growing trend to refer to height in centimeters. Whether being measured in hands and inches, or in centimeters, the height is always taken from the ground to the highest point of the withers, and for an accurate reading, the horse should be measured standing on a flat level surface, and without shoes.