A question asked by someone just like you.

Why do wheels spin so fast when a car moves?

Art by Paul Montgomery

With a little math, we can see how quickly the wheels must turn.

On a typical car, a tire is about 6½ (6.5) feet around the outside edge. Each time the tires complete a turn, the car has moved 6.5 feet.

How many times must the wheels turn to go one mile? There are 5,280 feet in a mile. When we divide 5,280 by 6.5, we see that the wheels must turn 812 times to cover the distance.

Now, how fast do the wheels turn when the car goes at a typical highway speed—about 60 miles per hour? There are 60 minutes in an hour, so at that speed the car is also going about one mile per minute, and every minute the wheels turn 812 times. Since there are 60 seconds in a minute, we can divide 812 by 60 to find that the wheels spin about 13.5 times a second. You’re right: that’s fast!