| Merthyr Tudful to Roy (Utah) | 4,727.67 mi (7,608.45 km) |
| Merthyr Tudful to Royal Kunia (Hawaii) | 7,155.05 mi (11,514.95 km) |
| Merthyr Tudful to Royal Oak (Michigan) | 3,613.18 mi (5,814.86 km) |
| Merthyr Tudful to Royal Palm Beach (Florida) | 4,242.07 mi (6,826.95 km) |
| Merthyr Tudful to Royse City (Texas) | 4,586.01 mi (7,380.47 km) |
| Merthyr Tudful to Ruskin (Florida) | 4,284.60 mi (6,895.40 km) |
| Merthyr Tudful to Russellville (Alabama) | 4,168.14 mi (6,707.97 km) |
| Merthyr Tudful to Russellville (Arkansas) | 4,345.70 mi (6,993.72 km) |
| Merthyr Tudful to Ruston (Louisiana) | 4,462.94 mi (7,182.41 km) |
| Merthyr Tudful to Rutherford (New Jersey) | 3,322.70 mi (5,347.37 km) |
| Merthyr Tudful to Rutland (Vermont) | 3,160.51 mi (5,086.35 km) |
| Merthyr Tudful to Sabana Grande (Puerto Rico) | 4,120.06 mi (6,630.60 km) |
| Merthyr Tudful to Sachse (Texas) | 4,596.43 mi (7,397.24 km) |
| Merthyr Tudful to Saco (Maine) | 3,060.88 mi (4,926.01 km) |
| Merthyr Tudful to Sacramento (California) | 5,170.63 mi (8,321.33 km) |
