Convert from tatami to square inch

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 (square inch)
The square inch is a traditional unit of area. 1 in² equals exactly 6.4516 cm² or 645.16 mm².