| Potomac to Rockville (Maryland) | 5.23 mi (8.41 km) |
| Potomac to Rockville Centre (New York) | 220.41 mi (354.71 km) |
| Potomac to Rockwall (Texas) | 1,152.78 mi (1,855.22 km) |
| Potomac to Rocky Mount (North Carolina) | 213.07 mi (342.90 km) |
| Potomac to Rocky Point (New York) | 261.59 mi (420.99 km) |
| Potomac to Rocky River (Ohio) | 298.52 mi (480.41 km) |
| Potomac to Roessleville (New York) | 310.23 mi (499.26 km) |
| Potomac to Rogers (Arkansas) | 944.59 mi (1,520.18 km) |
| Potomac to Rogers (Minnesota) | 939.60 mi (1,512.13 km) |
| Potomac to Rohnert Park (California) | 2,428.54 mi (3,908.35 km) |
| Potomac to Rolla (Missouri) | 790.46 mi (1,272.13 km) |
| Potomac to Rolling Meadows (Illinois) | 606.17 mi (975.54 km) |
| Potomac to Roma (Texas) | 1,531.37 mi (2,464.50 km) |
| Potomac to Rome (Georgia) | 550.93 mi (886.63 km) |
| Potomac to Rome (New York) | 304.20 mi (489.56 km) |
