| Watford to Karditsa | 1,364.57 mi (2,196.06 km) |
| Watford to Kastoria | 1,284.07 mi (2,066.50 km) |
| Watford to Katerini | 1,342.88 mi (2,161.15 km) |
| Watford to Keratsini | 1,497.86 mi (2,410.57 km) |
| Watford to Kerkyra | 1,278.46 mi (2,057.48 km) |
| Watford to Kiato | 1,463.57 mi (2,355.39 km) |
| Watford to Kifisia | 1,499.46 mi (2,413.15 km) |
| Watford to Kilkis | 1,323.52 mi (2,130.00 km) |
| Watford to Komotini | 1,419.11 mi (2,283.83 km) |
| Watford to Korinthos | 1,473.76 mi (2,371.79 km) |
| Watford to Koropi | 1,510.79 mi (2,431.37 km) |
| Watford to Korydallos | 1,498.26 mi (2,411.22 km) |
| Watford to Kos | 1,690.59 mi (2,720.75 km) |
| Watford to Kozani | 1,314.01 mi (2,114.69 km) |
| Watford to Lagos | 1,404.91 mi (2,260.98 km) |
