| Merthyr Tudful to Brownsburg (Indiana) | 3,861.06 mi (6,213.78 km) |
| Merthyr Tudful to Brownsville (Florida) | 4,287.24 mi (6,899.65 km) |
| Merthyr Tudful to Brownsville (Texas) | 4,993.09 mi (8,035.61 km) |
| Merthyr Tudful to Brownwood (Texas) | 4,754.65 mi (7,651.87 km) |
| Merthyr Tudful to Brunswick (Georgia) | 4,074.66 mi (6,557.54 km) |
| Merthyr Tudful to Brunswick (Ohio) | 3,616.27 mi (5,819.82 km) |
| Merthyr Tudful to Brushy Creek (Texas) | 4,768.44 mi (7,674.06 km) |
| Merthyr Tudful to Bryan (Texas) | 4,706.96 mi (7,575.12 km) |
| Merthyr Tudful to Bryant (Arkansas) | 4,353.05 mi (7,005.56 km) |
| Merthyr Tudful to Bryn Mawr-Skyway (Washington) | 4,688.36 mi (7,545.18 km) |
| Merthyr Tudful to Buckeye (Arizona) | 5,168.43 mi (8,317.79 km) |
| Merthyr Tudful to Buckhall (Virginia) | 3,551.74 mi (5,715.98 km) |
| Merthyr Tudful to Bucyrus (Ohio) | 3,681.79 mi (5,925.26 km) |
| Merthyr Tudful to Buda (Texas) | 4,795.45 mi (7,717.53 km) |
| Merthyr Tudful to Buena Park (California) | 5,327.25 mi (8,573.38 km) |
