| Willoughby to Kennewick (Washington) | 1,887.25 mi (3,037.23 km) |
| Willoughby to Kenosha (Wisconsin) | 337.77 mi (543.58 km) |
| Willoughby to Kent (Ohio) | 34.42 mi (55.39 km) |
| Willoughby to Kent (Washington) | 2,024.87 mi (3,258.71 km) |
| Willoughby to Kentwood (Michigan) | 230.41 mi (370.81 km) |
| Willoughby to Kerman (California) | 2,080.09 mi (3,347.58 km) |
| Willoughby to Kernersville (North Carolina) | 389.29 mi (626.50 km) |
| Willoughby to Kerrville (Texas) | 1,271.64 mi (2,046.51 km) |
| Willoughby to Kettering (Maryland) | 309.12 mi (497.48 km) |
| Willoughby to Kettering (Ohio) | 196.93 mi (316.94 km) |
| Willoughby to Kewanee (Illinois) | 441.89 mi (711.15 km) |
| Willoughby to Key Biscayne (Florida) | 1,104.67 mi (1,777.80 km) |
| Willoughby to Key Largo (Florida) | 1,143.09 mi (1,839.62 km) |
| Willoughby to Key West (Florida) | 1,180.42 mi (1,899.70 km) |
| Willoughby to Keystone (Florida) | 936.19 mi (1,506.65 km) |
