For five thousand years, the height of a horse has been measured in hands.
Body parts were our first points of reference for measurement.
For example, a foot was exactly that, the length of a Roman foot.
A hand was measured with the thumb curled into the palm, a distance now standardized as four inches.
A horse’s height is measured in a straight line from the ground to the withers, the top of the shoulders between the neck and the back.
A horse of 15.2 hands measures 15 times 4 inches, plus 2 inches, or 62 inches.
It’s important to keep in mind that you can have 15.3 hands, but after the next full inch the height is taken as 16 hands, not 15.4.
The hand is a tradition of British measurement.
In the rest of Europe a horse’s height is measured in meters and centimeters.
In some places, like Europe and South Africa, they measure in both hands and centimeters.