| Gaithersburg to Bonham (Texas) | 1,120.66 mi (1,803.53 km) |
| Gaithersburg to Bonita (California) | 2,254.27 mi (3,627.89 km) |
| Gaithersburg to Bonita Springs (Florida) | 921.69 mi (1,483.32 km) |
| Gaithersburg to Bonney Lake (Washington) | 2,299.28 mi (3,700.34 km) |
| Gaithersburg to Boone (Iowa) | 895.66 mi (1,441.42 km) |
| Gaithersburg to Boone (North Carolina) | 316.36 mi (509.13 km) |
| Gaithersburg to Borger (Texas) | 1,345.07 mi (2,164.68 km) |
| Gaithersburg to Bossier City (Louisiana) | 1,026.57 mi (1,652.11 km) |
| Gaithersburg to Boston (Massachusetts) | 388.88 mi (625.84 km) |
| Gaithersburg to Bostonia (California) | 2,245.78 mi (3,614.23 km) |
| Gaithersburg to Bothell (Washington) | 2,299.23 mi (3,700.25 km) |
| Gaithersburg to Bothell East (Washington) | 2,298.23 mi (3,698.64 km) |
| Gaithersburg to Bothell West (Washington) | 2,300.81 mi (3,702.80 km) |
| Gaithersburg to Boulder (Colorado) | 1,488.27 mi (2,395.14 km) |
| Gaithersburg to Boulder City (Nevada) | 2,065.18 mi (3,323.58 km) |
