| Potomac to Carpentras | 4,085.44 mi (6,574.88 km) |
| Potomac to Carquefou | 3,706.65 mi (5,965.28 km) |
| Potomac to Carqueiranne | 4,161.12 mi (6,696.68 km) |
| Potomac to Carrieres-sous-Poissy | 3,817.14 mi (6,143.09 km) |
| Potomac to Carrieres-sur-Seine | 3,828.64 mi (6,161.60 km) |
| Potomac to Carros | 4,189.50 mi (6,742.35 km) |
| Potomac to Carvin | 3,816.25 mi (6,141.65 km) |
| Potomac to Castanet-Tolosan | 3,941.65 mi (6,343.47 km) |
| Potomac to Castelginest | 3,933.54 mi (6,330.42 km) |
| Potomac to Castelnau-le-Lez | 4,046.81 mi (6,512.72 km) |
| Potomac to Castelnaudary | 3,968.14 mi (6,386.11 km) |
| Potomac to Castelsarrasin | 3,908.86 mi (6,290.70 km) |
| Potomac to Castres | 3,973.33 mi (6,394.46 km) |
| Potomac to Caudebec-les-Elbeuf | 3,765.91 mi (6,060.64 km) |
| Potomac to Caudry | 3,844.20 mi (6,186.63 km) |
