| Calera to Orbetello | 5,081.70 mi (8,178.21 km) |
| Calera to Oria | 5,434.32 mi (8,745.69 km) |
| Calera to Oristano | 5,050.20 mi (8,127.51 km) |
| Calera to Orta Nova | 5,318.97 mi (8,560.05 km) |
| Calera to Orte | 5,132.54 mi (8,260.03 km) |
| Calera to Ortona | 5,224.22 mi (8,407.57 km) |
| Calera to Orvieto | 5,111.38 mi (8,225.97 km) |
| Calera to Orzinuovi | 4,925.91 mi (7,927.49 km) |
| Calera to Osimo | 5,143.70 mi (8,277.98 km) |
| Calera to Ospitaletto | 4,926.73 mi (7,928.81 km) |
| Calera to Ostuni | 5,423.10 mi (8,727.64 km) |
| Calera to Ottaviano | 5,282.77 mi (8,501.80 km) |
| Calera to Ovada | 4,895.50 mi (7,878.55 km) |
| Calera to Ozieri | 5,046.09 mi (8,120.90 km) |
| Calera to Paceco | 5,300.87 mi (8,530.93 km) |
