Convert from tatami to cover

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 (cover)
The Cover is a traditional Welsh unit of area, standardized in the British system to be exactly 2/3 acre (about 0.2698 hectare). The word is an Anglicized version of the Welsh name cyfair for the unit.