| Potomac to Cadillac (Michigan) | 557.29 mi (896.87 km) |
| Potomac to Caguas (Puerto Rico) | 1,584.20 mi (2,549.52 km) |
| Potomac to Cahokia (Illinois) | 699.40 mi (1,125.58 km) |
| Potomac to Calabasas (California) | 2,305.76 mi (3,710.76 km) |
| Potomac to Caldwell (Idaho) | 2,052.73 mi (3,303.56 km) |
| Potomac to Caledonia (Wisconsin) | 615.44 mi (990.45 km) |
| Potomac to Calera (Alabama) | 670.20 mi (1,078.58 km) |
| Potomac to Calexico (California) | 2,172.52 mi (3,496.33 km) |
| Potomac to Calhoun (Georgia) | 530.20 mi (853.27 km) |
| Potomac to California (Maryland) | 62.29 mi (100.24 km) |
| Potomac to California City (California) | 2,239.18 mi (3,603.61 km) |
| Potomac to Callaway (Florida) | 775.55 mi (1,248.13 km) |
| Potomac to Calumet City (Illinois) | 573.97 mi (923.72 km) |
| Potomac to Calverton (Maryland) | 13.52 mi (21.75 km) |
| Potomac to Camano (Washington) | 2,315.85 mi (3,727.00 km) |
