| Gaithersburg to Joliet (Illinois) | 598.70 mi (963.52 km) |
| Gaithersburg to Jonesboro (Arkansas) | 772.16 mi (1,242.68 km) |
| Gaithersburg to Joplin (Missouri) | 949.17 mi (1,527.53 km) |
| Gaithersburg to Joppatowne (Maryland) | 50.07 mi (80.58 km) |
| Gaithersburg to Juana Díaz (Puerto Rico) | 1,591.96 mi (2,562.01 km) |
| Gaithersburg to Junction City (Kansas) | 1,051.21 mi (1,691.76 km) |
| Gaithersburg to Juneau (Alaska) | 2,806.05 mi (4,515.91 km) |
| Gaithersburg to Jupiter (Florida) | 860.36 mi (1,384.61 km) |
| Gaithersburg to Jupiter Farms (Florida) | 861.42 mi (1,386.32 km) |
| Gaithersburg to Jurupa Valley (California) | 2,243.39 mi (3,610.40 km) |
| Gaithersburg to Justice (Illinois) | 586.55 mi (943.96 km) |
| Gaithersburg to Kahului (Hawaii) | 4,760.17 mi (7,660.75 km) |
| Gaithersburg to Kailua (Hawaii) | 4,806.75 mi (7,735.71 km) |
| Gaithersburg to Kalamazoo (Michigan) | 489.09 mi (787.12 km) |
| Gaithersburg to Kalispell (Montana) | 1,936.11 mi (3,115.87 km) |
