thumb|Detail of the Ancient Egyptian cubit rod in the [[Museo Egizio of Turin, showing digit, palm, hand and fist lengths]]
thumb|Some hand-based measurements, including the digit (6)
The digit or finger is an ancient and obsolete non-SI unit of measurement of length. It was originally based on the breadth of a human finger. The width of an adult human male finger tip is indeed about 2 centimetres. In English this unit has mostly fallen out of use, as do others based on the human arm: finger (7/6 digit), palm (4 digits), hand (16/3 digits), shaftment (8 digits), span (12 digits), cubit (24 digits) and ell (60 digits).
Astronomy
In astronomy a digit is, or was until recently, one twelfth of the diameter of the sun or the moon.
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