| Gaithersburg to Hazleton (Pennsylvania) | 141.59 mi (227.86 km) |
| Gaithersburg to Healdsburg (California) | 2,429.23 mi (3,909.47 km) |
| Gaithersburg to Heath (Ohio) | 285.07 mi (458.78 km) |
| Gaithersburg to Heber (Utah) | 1,805.24 mi (2,905.25 km) |
| Gaithersburg to Helena (Alabama) | 672.98 mi (1,083.06 km) |
| Gaithersburg to Helena (Montana) | 1,819.99 mi (2,928.99 km) |
| Gaithersburg to Hemet (California) | 2,224.71 mi (3,580.32 km) |
| Gaithersburg to Henderson (Kentucky) | 567.42 mi (913.18 km) |
| Gaithersburg to Henderson (Nevada) | 2,067.55 mi (3,327.40 km) |
| Gaithersburg to Henderson (North Carolina) | 204.89 mi (329.74 km) |
| Gaithersburg to Henderson (Texas) | 1,096.06 mi (1,763.93 km) |
| Gaithersburg to Hendersonville (North Carolina) | 390.42 mi (628.32 km) |
| Gaithersburg to Hendersonville (Tennessee) | 548.63 mi (882.93 km) |
| Gaithersburg to Hercules (California) | 2,409.16 mi (3,877.17 km) |
| Gaithersburg to Hereford (Texas) | 1,416.91 mi (2,280.30 km) |
