Kilometers vs. Miles: A Traveler's Guide

You rent a car in Europe, look at the speed limit sign, and see "100". If you drive 100 mph, you will get arrested. If you drive 100 km/h, you are going about 62 mph.

The Fibonacci Trick

A fun math trick for converting miles to kilometers uses the Fibonacci sequence (1, 1, 2, 3, 5, 8, 13, 21...). The next number in the sequence is roughly the kilometer equivalent of the previous mile number.

• 3 miles is approx 5 km.
• 5 miles is approx 8 km.
• 8 miles is approx 13 km.

Mental Math for Speed

To roughly convert km/h to mph, cut the number in half and add a little bit back. 100 halved is 50. Add a bit (12) -> 62 mph. Accurate enough to keep you safe!