Fort Pierce is located at (27.438817, -80.335471) [REF].
According to the U. S. Census Bureau, the city has a total area of 20.8 mi² (53.8 km²), of which 14.7 square miles (38.2 km²) is land and 6.0 square miles (15.6 km²) of it (35.00%) is water.