To convert kilometers (km) to miles, use the conversion factor: 1 kilometer ≈ 0.621371 miles.
For a 20k (20 kilometers): 20km×0.621371miles/km-12.42742miles.
So, a 20k is approximately 12.43 miles.
This is a common distance in running events, like a 20k race, which is just slightly longer than a half marathon (13.1 miles).