Convert from legua to square mile

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.

Unit Definition (square mile)
The square mile is a traditional unit of area. One square mile is equal to 640 acres, 3 097 600 square yards, 258.9988 hectares, or 2.589 988 square kilometers.