Convert from football field [U.S.] to palm [Britain, Roman minor]

Unit Definition (football field [U.S.])
The football field is a common informal unit of distance in the United States and Canada. Americans aren't quite agreed as to whether the unit is exactly 100 yards (91.44 meters), the distance between the goal lines on an American football field, or 120 yards (109.728 meters), the distance including the two end zones. Canadian football fields are 110 yards (100.58 meters) long between the goal lines and 150 yards (137.16 meters) including the end zones. The football field is also used sometimes as an informal unit of area: including the end zones, an American football field represents an area of 1.3223 acre or about 0.535 hectare while the Canadian football field has an area of 2.0145 acre or 0.815 hectare.

Unit Definition (palm [Britain, Roman minor])
A palm, when used as a unit of length, is usually four digits or three inches, i.e. 7.62 cm (for the international inch). The width of an adult human male palm is indeed about 10 centimetres.In English this unit has mostly fallen out of use, as do others based on the human arm: digit (¼ palm), finger (7/24 palm), hand (4/3 palms), shaftment (2 palms), span (3 palms), cubit (6 palms) and ell (15 palms).