| Watford to Kidbrooke | 22.53 mi (36.27 km) |
| Watford to Kidderminster | 93.68 mi (150.77 km) |
| Watford to Kidlington | 40.03 mi (64.42 km) |
| Watford to Kidsgrove | 126.08 mi (202.91 km) |
| Watford to Killamarsh | 121.35 mi (195.30 km) |
| Watford to Killingworth | 238.16 mi (383.28 km) |
| Watford to Kilmarnock | 320.70 mi (516.12 km) |
| Watford to Kilsyth | 334.01 mi (537.54 km) |
| Watford to Kilwinning | 327.72 mi (527.41 km) |
| Watford to King's Lynn | 83.04 mi (133.64 km) |
| Watford to Kings Norton | 83.30 mi (134.06 km) |
| Watford to Kingsnorth | 65.70 mi (105.73 km) |
| Watford to Kingsteignton | 158.59 mi (255.22 km) |
| Watford to Kingston upon Hull | 144.39 mi (232.37 km) |
| Watford to Kingston upon Thames | 17.41 mi (28.01 km) |
