| Calhoun to Oerlinghausen | 4,528.21 mi (7,287.44 km) |
| Calhoun to Oestrich-Winkel | 4,560.61 mi (7,339.59 km) |
| Calhoun to Offenburg | 4,604.34 mi (7,409.96 km) |
| Calhoun to Oftersheim | 4,603.17 mi (7,408.09 km) |
| Calhoun to Ohrdruf | 4,642.88 mi (7,471.99 km) |
| Calhoun to Ohringen | 4,645.33 mi (7,475.94 km) |
| Calhoun to Olbernhau | 4,748.46 mi (7,641.91 km) |
| Calhoun to Olching | 4,750.80 mi (7,645.68 km) |
| Calhoun to Oldenburg | 4,476.65 mi (7,204.47 km) |
| Calhoun to Oldenburg in Holstein | 4,541.33 mi (7,308.57 km) |
| Calhoun to Olfen | 4,485.84 mi (7,219.26 km) |
| Calhoun to Olpe | 4,523.80 mi (7,280.36 km) |
| Calhoun to Olsberg | 4,539.39 mi (7,305.45 km) |
| Calhoun to Oranienburg | 4,675.95 mi (7,525.21 km) |
| Calhoun to Ortenberg | 4,591.81 mi (7,389.81 km) |
