| Potomac to Cognac | 3,798.90 mi (6,113.74 km) |
| Potomac to Cogolin | 4,176.56 mi (6,721.52 km) |
| Potomac to Colmar | 4,064.10 mi (6,540.54 km) |
| Potomac to Colombes | 3,826.76 mi (6,158.58 km) |
| Potomac to Colomiers | 3,931.47 mi (6,327.09 km) |
| Potomac to Combs-la-Ville | 3,846.32 mi (6,190.05 km) |
| Potomac to Comines | 3,811.58 mi (6,134.15 km) |
| Potomac to Compiegne | 3,838.05 mi (6,176.75 km) |
| Potomac to Concarneau | 3,586.74 mi (5,772.31 km) |
| Potomac to Conde-sur-l'Escaut | 3,843.24 mi (6,185.10 km) |
| Potomac to Conflans-Sainte-Honorine | 3,818.34 mi (6,145.02 km) |
| Potomac to Corbas | 4,030.54 mi (6,486.52 km) |
| Potomac to Corbeil-Essonnes | 3,844.49 mi (6,187.10 km) |
| Potomac to Cormeilles-en-Parisis | 3,823.33 mi (6,153.05 km) |
| Potomac to Cosne sur Loire | 3,895.45 mi (6,269.12 km) |
