Wailua Homesteads is located at (22.064507, -159.383875)
According to the United States Census Bureau, the CDP has a total area of 7.1 square miles (18.5 km²), of which, 7.0 square miles (18.2 km²) of it is land and 0.1 square miles (0.3 km²) of it (1.40%) is water.