| Merthyr Tudful to Carlsbad (New Mexico) | 4,919.47 mi (7,917.13 km) |
| Merthyr Tudful to Carmel (Indiana) | 3,845.66 mi (6,188.99 km) |
| Merthyr Tudful to Carmichael (California) | 5,162.63 mi (8,308.45 km) |
| Merthyr Tudful to Carney (Maryland) | 3,483.52 mi (5,606.18 km) |
| Merthyr Tudful to Carnot-Moon (Pennsylvania) | 3,584.43 mi (5,768.59 km) |
| Merthyr Tudful to Carol Stream (Illinois) | 3,833.12 mi (6,168.81 km) |
| Merthyr Tudful to Carolina (Puerto Rico) | 4,061.45 mi (6,536.27 km) |
| Merthyr Tudful to Carolina Forest (South Carolina) | 3,841.40 mi (6,182.13 km) |
| Merthyr Tudful to Carpentersville (Illinois) | 3,829.85 mi (6,163.55 km) |
| Merthyr Tudful to Carpinteria (California) | 5,346.19 mi (8,603.86 km) |
| Merthyr Tudful to Carrboro (North Carolina) | 3,747.12 mi (6,030.40 km) |
| Merthyr Tudful to Carroll (Iowa) | 4,080.30 mi (6,566.61 km) |
| Merthyr Tudful to Carrollton (Georgia) | 4,105.47 mi (6,607.12 km) |
| Merthyr Tudful to Carrollton (Texas) | 4,608.11 mi (7,416.03 km) |
| Merthyr Tudful to Carrollwood (Florida) | 4,270.97 mi (6,873.46 km) |
