| Boulogne-sur-Mer to Karlovo | 1,225.88 mi (1,972.87 km) |
| Boulogne-sur-Mer to Karnobat | 1,317.47 mi (2,120.26 km) |
| Boulogne-sur-Mer to Kavarna | 1,345.12 mi (2,164.76 km) |
| Boulogne-sur-Mer to Kazanlak | 1,251.65 mi (2,014.33 km) |
| Boulogne-sur-Mer to Knezha | 1,162.40 mi (1,870.70 km) |
| Boulogne-sur-Mer to Kostinbrod | 1,153.17 mi (1,855.85 km) |
| Boulogne-sur-Mer to Kozloduy | 1,137.06 mi (1,829.93 km) |
| Boulogne-sur-Mer to Kyustendil | 1,153.41 mi (1,856.24 km) |
| Boulogne-sur-Mer to Levski | 1,211.54 mi (1,949.79 km) |
| Boulogne-sur-Mer to Lom | 1,114.70 mi (1,793.94 km) |
| Boulogne-sur-Mer to Lovech | 1,202.91 mi (1,935.90 km) |
| Boulogne-sur-Mer to Lukovit | 1,177.38 mi (1,894.81 km) |
| Boulogne-sur-Mer to Lyaskovets | 1,246.21 mi (2,005.58 km) |
| Boulogne-sur-Mer to Mezdra | 1,159.90 mi (1,866.67 km) |
| Boulogne-sur-Mer to Momchilgrad | 1,296.47 mi (2,086.47 km) |
