There are 1.60934 kilometers in a mile so... 50 miles * 1.60934 k/mi = 80.467 kilometers 50 miles = 80.47 km. Every mile is about 1.6 km so its about 80 km. The formula to convert miles to km . 50 mi . * . 63360 in 1 mi . * . 2.54 cm 1 in . * . 1 km 100000 cm . = . 80.4672 km.