| Ridderkerk to Karlovo | 1,135.92 mi (1,828.09 km) |
| Ridderkerk to Karnobat | 1,220.95 mi (1,964.93 km) |
| Ridderkerk to Kavarna | 1,241.01 mi (1,997.21 km) |
| Ridderkerk to Kazanlak | 1,159.93 mi (1,866.73 km) |
| Ridderkerk to Knezha | 1,069.78 mi (1,721.65 km) |
| Ridderkerk to Kostinbrod | 1,067.67 mi (1,718.26 km) |
| Ridderkerk to Kozloduy | 1,043.84 mi (1,679.90 km) |
| Ridderkerk to Kyustendil | 1,073.18 mi (1,727.12 km) |
| Ridderkerk to Levski | 1,116.43 mi (1,796.72 km) |
| Ridderkerk to Lom | 1,022.85 mi (1,646.11 km) |
| Ridderkerk to Lovech | 1,110.42 mi (1,787.05 km) |
| Ridderkerk to Lukovit | 1,086.29 mi (1,748.21 km) |
| Ridderkerk to Lyaskovets | 1,150.85 mi (1,852.11 km) |
| Ridderkerk to Mezdra | 1,070.67 mi (1,723.08 km) |
| Ridderkerk to Momchilgrad | 1,210.58 mi (1,948.24 km) |
