How is the height of a horse traditionally measured?

The height of a horse is measured in hands. One hand is equal to 4 inches. If a horse does not match up with accurately with just hands, then they will also use inches to specify the remainder. For example, a horse that is 10.2 h means 10 hands and 2 inches.

The height of a horse refers to its height up to where the neck meets its back, rather than all the way up to its head, because the head continually changes level depending on a horse's position.

The origin of measuring a horse this way is very old but easy to understand. In days long ago people did not have the common measuring devices (like tape measures, etc.) that we do today. To measure a horse, they used their hands. At various times in history and in different locales a "hand" was defined as the with of a person's hand using the fingers only, the width of a person's hand using the fingers and the thumb, the height of a clenched fist, and possibly others. Though the origins are ancient, a hand is still the unit of measurement for horses that modern horse owners use today.