What are cubit, hand-span, arm-length, and foot-span?

Cubit, hand-span, arm-length, and foot-span are traditional units of measurement based on different parts of the human body. Before standard units like metres and centimetres were developed, people used these body-based measurements to estimate length and distance.

A cubit is the approximate distance from the elbow to the tip of the middle finger. A hand-span is the distance between the tip of the thumb and the tip of the little finger when the hand is fully stretched. Arm-length refers to the length of a person’s arm, usually measured from the shoulder to the fingertips. A foot-span is the length of a person’s foot from heel to toe.

These measurements were easy to use in daily life, but they were not always accurate because body sizes vary from person to person. Modern science uses standard units to ensure accurate and consistent measurements.