Conversion Center

Cubit is a historic unit of length used as a standard of measurement. This unit is defined as the length of a man's forearm from his elbow to the tip of his middle finger. Usually it was equal to 24 digits. One digit in English system is 3/4 of an inch, that makes a cubit 18 inches or 45.72 cm long.

Astronomers use astronomical unit (ua or au or AU) as yardstick for measuring the distances between objects in the Solar System. AU is defined as the distance from the center of the Earth to the center of the Sun. Currently it is accepted that this length is 149 597 870 691 meters, with an uncertainty of about 30 meters.