| Merthyr Tudful to Robertsville (New Jersey) | 3,351.08 mi (5,393.05 km) |
| Merthyr Tudful to Robinson (Texas) | 4,695.69 mi (7,556.98 km) |
| Merthyr Tudful to Robstown (Texas) | 4,907.30 mi (7,897.54 km) |
| Merthyr Tudful to Rochester (Michigan) | 3,604.00 mi (5,800.08 km) |
| Merthyr Tudful to Rochester (Minnesota) | 3,900.53 mi (6,277.29 km) |
| Merthyr Tudful to Rochester (New Hampshire) | 3,091.61 mi (4,975.46 km) |
| Merthyr Tudful to Rochester (New York) | 3,365.44 mi (5,416.15 km) |
| Merthyr Tudful to Rochester Hills (Michigan) | 3,606.41 mi (5,803.95 km) |
| Merthyr Tudful to Rock Hill (South Carolina) | 3,873.33 mi (6,233.52 km) |
| Merthyr Tudful to Rock Island (Illinois) | 3,947.78 mi (6,353.33 km) |
| Merthyr Tudful to Rock Springs (Wyoming) | 4,611.43 mi (7,421.38 km) |
| Merthyr Tudful to Rockford (Illinois) | 3,853.22 mi (6,201.16 km) |
| Merthyr Tudful to Rockledge (Florida) | 4,182.92 mi (6,731.76 km) |
| Merthyr Tudful to Rocklin (California) | 5,150.27 mi (8,288.56 km) |
| Merthyr Tudful to Rockport (Texas) | 4,871.18 mi (7,839.40 km) |
