| Merthyr Tudful to Kaneohe (Hawaii) | 7,150.74 mi (11,508.01 km) |
| Merthyr Tudful to Kankakee (Illinois) | 3,860.35 mi (6,212.63 km) |
| Merthyr Tudful to Kannapolis (North Carolina) | 3,832.29 mi (6,167.48 km) |
| Merthyr Tudful to Kansas City (Kansas) | 4,218.22 mi (6,788.58 km) |
| Merthyr Tudful to Kansas City (Missouri) | 4,210.99 mi (6,776.94 km) |
| Merthyr Tudful to Kapaa (Hawaii) | 7,131.90 mi (11,477.69 km) |
| Merthyr Tudful to Kapolei (Hawaii) | 7,160.03 mi (11,522.96 km) |
| Merthyr Tudful to Katy (Texas) | 4,730.38 mi (7,612.81 km) |
| Merthyr Tudful to Kaukauna (Wisconsin) | 3,731.37 mi (6,005.06 km) |
| Merthyr Tudful to Kaysville (Utah) | 4,731.93 mi (7,615.30 km) |
| Merthyr Tudful to Kearney (Missouri) | 4,192.36 mi (6,746.95 km) |
| Merthyr Tudful to Kearney (Nebraska) | 4,302.02 mi (6,923.43 km) |
| Merthyr Tudful to Kearns (Utah) | 4,754.26 mi (7,651.25 km) |
| Merthyr Tudful to Kearny (New Jersey) | 3,326.18 mi (5,352.97 km) |
| Merthyr Tudful to Keene (New Hampshire) | 3,159.74 mi (5,085.10 km) |
