| Rockville to Reedley (California) | 2,293.18 mi (3,690.52 km) |
| Rockville to Reidsville (North Carolina) | 234.33 mi (377.12 km) |
| Rockville to Reisterstown (Maryland) | 31.50 mi (50.70 km) |
| Rockville to Rendon (Texas) | 1,207.97 mi (1,944.04 km) |
| Rockville to Reno (Nevada) | 2,260.49 mi (3,637.91 km) |
| Rockville to Renton (Washington) | 2,303.83 mi (3,707.65 km) |
| Rockville to Republic (Missouri) | 894.33 mi (1,439.28 km) |
| Rockville to Reston (Virginia) | 13.79 mi (22.20 km) |
| Rockville to Revere (Massachusetts) | 395.78 mi (636.94 km) |
| Rockville to Rexburg (Idaho) | 1,809.63 mi (2,912.31 km) |
| Rockville to Reynoldsburg (Ohio) | 306.52 mi (493.29 km) |
| Rockville to Rialto (California) | 2,239.50 mi (3,604.13 km) |
| Rockville to Richardson (Texas) | 1,168.43 mi (1,880.40 km) |
| Rockville to Richfield (Minnesota) | 917.79 mi (1,477.04 km) |
| Rockville to Richfield (Wisconsin) | 643.42 mi (1,035.49 km) |
