Convert from tatami to legua

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 (legua)
The legua is a traditional Spanish unit of area equal to one square legua (the Spanish league). In Spanish-speaking Latin America and the southwestern states of the U.S. land was customarily measured in leguas, with 1 legua equal to 25 labors (see above) or 25 million square varas. Using the Texas definition of the vara as the starting point, the legua is 4428.4 acres, 6.919 square miles, 1792 hectares, or 17.92 square kilometers. A slightly larger figure, 4439 acres (1796 hectares), is used in California. Larger sizes, between 1800 and 1900 hectares, were formerly used in some parts of South America. In Mexico and Texas, this unit is often called a sitio.