Convert from football field [U.S.] to gry

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 (gry)
The gry is a proposed unit of distance in the English traditional system. The name was first used in June 1679 by the philosopher John Locke (1632-1704) as a unit equal to 0.001 foot, 0.01 inch, or 0.1 line in a decimalized distance system. (Thomas Jefferson, who was very familiar with Locke's writings, later proposed a similar system in the U.S., but he called 0.001 foot a point rather than a gry.) In 1813, the gry was revived in another decimal measurement scheme in Britain. All these ideas failed, but the gry had some limited use in the nineteenth century as a unit equal to 0.1 line or 1/120 inch (0.211 667 millimeter). Long forgotten, the gry recently came back into the limelight in connection with a puzzle, circulating on the Internet, which asked for three English words ending in -gry. The word "gry" is from the ancient Greek, where it meant "a trifling amount".