| Karlovo to Obernburg am Main | 895.92 mi (1,441.84 km) |
| Karlovo to Obernkirchen | 985.77 mi (1,586.44 km) |
| Karlovo to Oberschleissheim | 748.13 mi (1,204.00 km) |
| Karlovo to Oberstdorf | 780.55 mi (1,256.17 km) |
| Karlovo to Obertraubling | 747.75 mi (1,203.39 km) |
| Karlovo to Obertshausen | 915.34 mi (1,473.10 km) |
| Karlovo to Oberursel | 929.80 mi (1,496.37 km) |
| Karlovo to Ochsenfurt | 853.33 mi (1,373.29 km) |
| Karlovo to Ochsenhausen | 811.21 mi (1,305.51 km) |
| Karlovo to Ochtrup | 1,050.99 mi (1,691.41 km) |
| Karlovo to Odenthal | 1,013.23 mi (1,630.64 km) |
| Karlovo to Oelde | 1,002.76 mi (1,613.78 km) |
| Karlovo to Oelsnitz | 803.93 mi (1,293.79 km) |
| Karlovo to Oer-Erkenschwick | 1,028.67 mi (1,655.48 km) |
| Karlovo to Oerlinghausen | 989.46 mi (1,592.39 km) |
