| Potomac to Romeoville (Illinois) | 601.77 mi (968.45 km) |
| Potomac to Romulus (Michigan) | 392.19 mi (631.17 km) |
| Potomac to Ronkonkoma (New York) | 248.58 mi (400.05 km) |
| Potomac to Roosevelt (New York) | 223.42 mi (359.56 km) |
| Potomac to Rosamond (California) | 2,264.20 mi (3,643.87 km) |
| Potomac to Rosaryville (Maryland) | 26.12 mi (42.03 km) |
| Potomac to Roscoe (Illinois) | 661.33 mi (1,064.31 km) |
| Potomac to Rose Hill (Virginia) | 16.34 mi (26.30 km) |
| Potomac to Roseburg (Oregon) | 2,389.49 mi (3,845.51 km) |
| Potomac to Rosedale (California) | 2,305.10 mi (3,709.69 km) |
| Potomac to Rosedale (Maryland) | 42.62 mi (68.58 km) |
| Potomac to Roselle (Illinois) | 607.34 mi (977.41 km) |
| Potomac to Roselle (New Jersey) | 192.49 mi (309.78 km) |
| Potomac to Roselle Park (New Jersey) | 192.70 mi (310.12 km) |
| Potomac to Rosemead (California) | 2,276.04 mi (3,662.94 km) |
