| Gaithersburg to Karlovo | 4,975.89 mi (8,007.92 km) |
| Gaithersburg to Karnobat | 5,063.86 mi (8,149.50 km) |
| Gaithersburg to Kavarna | 5,082.75 mi (8,179.90 km) |
| Gaithersburg to Kazanlak | 5,001.00 mi (8,048.34 km) |
| Gaithersburg to Knezha | 4,911.20 mi (7,903.81 km) |
| Gaithersburg to Kostinbrod | 4,903.99 mi (7,892.21 km) |
| Gaithersburg to Kozloduy | 4,885.50 mi (7,862.45 km) |
| Gaithersburg to Kyustendil | 4,903.80 mi (7,891.90 km) |
| Gaithersburg to Levski | 4,958.91 mi (7,980.59 km) |
| Gaithersburg to Lom | 4,863.80 mi (7,827.52 km) |
| Gaithersburg to Lovech | 4,951.83 mi (7,969.20 km) |
| Gaithersburg to Lukovit | 4,926.90 mi (7,929.09 km) |
| Gaithersburg to Lyaskovets | 4,993.43 mi (8,036.16 km) |
| Gaithersburg to Mezdra | 4,910.05 mi (7,901.97 km) |
| Gaithersburg to Momchilgrad | 5,047.31 mi (8,122.86 km) |
