| Potomac to Robertsville (New Jersey) | 179.36 mi (288.65 km) |
| Potomac to Robinson (Texas) | 1,236.48 mi (1,989.92 km) |
| Potomac to Robstown (Texas) | 1,407.43 mi (2,265.05 km) |
| Potomac to Rochester (Michigan) | 400.19 mi (644.04 km) |
| Potomac to Rochester (Minnesota) | 861.21 mi (1,385.98 km) |
| Potomac to Rochester (New Hampshire) | 438.17 mi (705.17 km) |
| Potomac to Rochester (New York) | 287.85 mi (463.24 km) |
| Potomac to Rochester Hills (Michigan) | 400.74 mi (644.93 km) |
| Potomac to Rock Hill (South Carolina) | 351.87 mi (566.27 km) |
| Potomac to Rock Island (Illinois) | 725.39 mi (1,167.41 km) |
| Potomac to Rock Springs (Wyoming) | 1,687.19 mi (2,715.27 km) |
| Potomac to Rockford (Illinois) | 660.82 mi (1,063.48 km) |
| Potomac to Rockledge (Florida) | 766.24 mi (1,233.14 km) |
| Potomac to Rocklin (California) | 2,344.76 mi (3,773.53 km) |
| Potomac to Rockport (Texas) | 1,368.84 mi (2,202.94 km) |
