| Potomac to Caldicot | 3,557.21 mi (5,724.78 km) |
| Potomac to Calne | 3,590.91 mi (5,779.01 km) |
| Potomac to Cam | 3,570.77 mi (5,746.60 km) |
| Potomac to Camberley | 3,644.91 mi (5,865.91 km) |
| Potomac to Camborne | 3,478.02 mi (5,597.33 km) |
| Potomac to Cambridge | 3,660.92 mi (5,891.68 km) |
| Potomac to Cambuslang | 3,426.60 mi (5,514.58 km) |
| Potomac to Canford Cliffs | 3,609.61 mi (5,809.11 km) |
| Potomac to Cannock | 3,564.64 mi (5,736.74 km) |
| Potomac to Canterbury | 3,720.56 mi (5,987.66 km) |
| Potomac to Carlisle | 3,488.20 mi (5,613.72 km) |
| Potomac to Carlton Colville | 3,718.25 mi (5,983.95 km) |
| Potomac to Carluke | 3,440.52 mi (5,536.98 km) |
| Potomac to Carnoustie | 3,470.79 mi (5,585.69 km) |
| Potomac to Carshalton | 3,667.74 mi (5,902.66 km) |
