Ranchitos Las Lomas is located at (27.628277, -99.234505) [REF].
According to the United States Census Bureau in 2000, the CDP has a total area of 21.9 square miles (56.8 km²), of which, 21.8 square miles (56.6 km²) of it is land and 0.1 square miles (0.2 km²) of it (0.37%) is water.