| Merthyr Tudful to Carson (California) | 5,336.68 mi (8,588.56 km) |
| Merthyr Tudful to Carson City (Nevada) | 5,084.60 mi (8,182.87 km) |
| Merthyr Tudful to Carteret (New Jersey) | 3,337.83 mi (5,371.72 km) |
| Merthyr Tudful to Cartersville (Georgia) | 4,065.69 mi (6,543.10 km) |
| Merthyr Tudful to Carthage (Missouri) | 4,298.98 mi (6,918.55 km) |
| Merthyr Tudful to Cary (Illinois) | 3,824.18 mi (6,154.43 km) |
| Merthyr Tudful to Cary (North Carolina) | 3,742.71 mi (6,023.30 km) |
| Merthyr Tudful to Casa de Oro-Mount Helix (California) | 5,354.16 mi (8,616.70 km) |
| Merthyr Tudful to Casa Grande (Arizona) | 5,166.29 mi (8,314.35 km) |
| Merthyr Tudful to Casas Adobes (Arizona) | 5,170.53 mi (8,321.16 km) |
| Merthyr Tudful to Cascades (Virginia) | 3,534.87 mi (5,688.82 km) |
| Merthyr Tudful to Casper (Wyoming) | 4,448.85 mi (7,159.73 km) |
| Merthyr Tudful to Casselberry (Florida) | 4,190.60 mi (6,744.12 km) |
| Merthyr Tudful to Castaic (California) | 5,312.63 mi (8,549.86 km) |
| Merthyr Tudful to Castle Pines (Colorado) | 4,572.73 mi (7,359.10 km) |
