A finger (sometimes finger-breadth), when used as a unit, is usually seven eighth of an inch or 2.2225 cm (for the international inch). The width of an adult human male finger tip is indeed about 2 centimetres. The inch, on the other hand, originates in the breadth of a thumb. In English this unit has mostly fallen out of use, as do others based on the human arm: digit (6/7 finger), palm (24/7 finger), hand (32/7 fingers), shaftment (48/7 fingers), span (72/7 fingers), cubit (144/7 fingers) and ell (360/7 fingers).