| Rockville to Jacksonville (North Carolina) | 301.16 mi (484.66 km) |
| Rockville to Jacksonville (Texas) | 1,127.98 mi (1,815.31 km) |
| Rockville to Jacksonville Beach (Florida) | 654.31 mi (1,053.02 km) |
| Rockville to James Island (South Carolina) | 465.39 mi (748.97 km) |
| Rockville to Jamestown (New York) | 235.14 mi (378.42 km) |
| Rockville to Jamestown (North Dakota) | 1,209.85 mi (1,947.06 km) |
| Rockville to Janesville (Wisconsin) | 666.81 mi (1,073.13 km) |
| Rockville to Jasmine Estates (Florida) | 810.18 mi (1,303.85 km) |
| Rockville to Jasper (Alabama) | 667.66 mi (1,074.49 km) |
| Rockville to Jasper (Indiana) | 529.23 mi (851.72 km) |
| Rockville to Jefferson (Georgia) | 494.34 mi (795.56 km) |
| Rockville to Jefferson (Louisiana) | 970.25 mi (1,561.47 km) |
| Rockville to Jefferson City (Missouri) | 808.39 mi (1,300.98 km) |
| Rockville to Jefferson Hills (Pennsylvania) | 169.67 mi (273.05 km) |
| Rockville to Jefferson Valley-Yorktown (New York) | 234.86 mi (377.97 km) |
