| Merthyr Tudful to Isny im Allgau | 660.22 mi (1,062.52 km) |
| Merthyr Tudful to Isselburg | 420.48 mi (676.70 km) |
| Merthyr Tudful to Issum | 420.20 mi (676.24 km) |
| Merthyr Tudful to Itzehoe | 558.05 mi (898.10 km) |
| Merthyr Tudful to Jena | 647.26 mi (1,041.67 km) |
| Merthyr Tudful to Jever | 488.74 mi (786.56 km) |
| Merthyr Tudful to Jork | 560.52 mi (902.08 km) |
| Merthyr Tudful to Juchen | 427.64 mi (688.22 km) |
| Merthyr Tudful to Julich | 423.79 mi (682.03 km) |
| Merthyr Tudful to Juterbog | 700.56 mi (1,127.44 km) |
| Merthyr Tudful to Kaarst | 431.27 mi (694.06 km) |
| Merthyr Tudful to Kaiserslautern | 513.45 mi (826.32 km) |
| Merthyr Tudful to Kalkar | 413.44 mi (665.36 km) |
| Merthyr Tudful to Kall | 437.78 mi (704.53 km) |
| Merthyr Tudful to Kaltenkirchen | 574.86 mi (925.15 km) |
