| Hertford to Karlovo | 1,318.69 mi (2,122.23 km) |
| Hertford to Karnobat | 1,407.85 mi (2,265.72 km) |
| Hertford to Kavarna | 1,432.12 mi (2,304.78 km) |
| Hertford to Kazanlak | 1,343.85 mi (2,162.71 km) |
| Hertford to Knezha | 1,254.14 mi (2,018.35 km) |
| Hertford to Kostinbrod | 1,247.42 mi (2,007.52 km) |
| Hertford to Kozloduy | 1,228.54 mi (1,977.14 km) |
| Hertford to Kyustendil | 1,249.29 mi (2,010.54 km) |
| Hertford to Levski | 1,302.38 mi (2,095.97 km) |
| Hertford to Lom | 1,206.66 mi (1,941.93 km) |
| Hertford to Lovech | 1,294.76 mi (2,083.71 km) |
| Hertford to Lukovit | 1,269.72 mi (2,043.41 km) |
| Hertford to Lyaskovets | 1,336.98 mi (2,151.67 km) |
| Hertford to Mezdra | 1,252.88 mi (2,016.32 km) |
| Hertford to Momchilgrad | 1,390.77 mi (2,238.23 km) |
