| Merthyr Tudful to Medford (New York) | 3,276.56 mi (5,273.11 km) |
| Merthyr Tudful to Medford (Oregon) | 4,997.09 mi (8,042.03 km) |
| Merthyr Tudful to Medina (Ohio) | 3,623.16 mi (5,830.92 km) |
| Merthyr Tudful to Medulla (Florida) | 4,253.77 mi (6,845.78 km) |
| Merthyr Tudful to Mehlville (Missouri) | 4,077.90 mi (6,562.74 km) |
| Merthyr Tudful to Melbourne (Florida) | 4,190.36 mi (6,743.74 km) |
| Merthyr Tudful to Melissa (Texas) | 4,579.43 mi (7,369.88 km) |
| Merthyr Tudful to Melrose (Massachusetts) | 3,129.10 mi (5,035.80 km) |
| Merthyr Tudful to Melrose Park (Illinois) | 3,823.52 mi (6,153.37 km) |
| Merthyr Tudful to Melville (New York) | 3,295.66 mi (5,303.86 km) |
| Merthyr Tudful to Melvindale (Michigan) | 3,624.21 mi (5,832.60 km) |
| Merthyr Tudful to Memphis (Florida) | 4,298.67 mi (6,918.04 km) |
| Merthyr Tudful to Memphis (Tennessee) | 4,228.48 mi (6,805.09 km) |
| Merthyr Tudful to Menasha (Wisconsin) | 3,740.42 mi (6,019.62 km) |
| Merthyr Tudful to Mendota (California) | 5,239.87 mi (8,432.76 km) |
