Convert from tatami to perch

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 (perch)
The perch is a unit of area. A perch of area covers exactly 272.25 square feet or about 25.292 85 square meters. There are 40 perches in a rood and 160 perches in an acre.