| Calumet City to Opwijk | 4,138.21 mi (6,659.81 km) |
| Calumet City to Ostend | 4,081.73 mi (6,568.91 km) |
| Calumet City to Oud-Heverlee | 4,161.04 mi (6,696.55 km) |
| Calumet City to Oud-Turnhout | 4,155.89 mi (6,688.25 km) |
| Calumet City to Oudenaarde | 4,120.27 mi (6,630.94 km) |
| Calumet City to Oudenburg | 4,086.21 mi (6,576.12 km) |
| Calumet City to Oupeye | 4,202.08 mi (6,762.60 km) |
| Calumet City to Overijse | 4,157.79 mi (6,691.31 km) |
| Calumet City to Overpelt | 4,175.52 mi (6,719.86 km) |
| Calumet City to Paal | 4,172.73 mi (6,715.36 km) |
| Calumet City to Peer | 4,179.87 mi (6,726.86 km) |
| Calumet City to Pepinster | 4,213.67 mi (6,781.24 km) |
| Calumet City to Peruwelz | 4,131.17 mi (6,648.47 km) |
| Calumet City to Perwez | 4,174.00 mi (6,717.40 km) |
| Calumet City to Philippeville | 4,178.99 mi (6,725.44 km) |
