Convert from tatami to oxgang

Unit Definition (tatami)
The tatami is a Japanese unit of area equal to the area of a traditional tatami mat, 0.5 ken by 1 ken or about 90 centimeters by 180 centimeters (roughly 1.62 square meters or 17.5 square feet). This unit, used especially for measuring the area of rooms in houses and apartments, is also called the jo.

Unit Definition (oxgang)
The oxgang is an old English unit of land area equal to 1/8 hide or roughly 15 acres (6 hectares). The hide was considered the area a farmer could plow with a team of 8 oxen, so an oxgang was the area he could plow with a single ox. The unit was also called the bovate, from the Latin word bos for an ox or cow.