mph stands for “miles per hour,” a measurement that tells you how fast something is moving. If a car travels at 60 mph, it means that car would cover 60 miles in one hour if it kept going at that same speed.

Speed limits on highways are posted in mph: you might see signs saying 65 mph or 70 mph. When weather forecasters warn about dangerous storms, they'll report wind speeds in mph. A hurricane with 100 mph winds is far more dangerous than one with 75 mph winds.

Athletes use mph too. Baseball scouts measure how fast pitchers throw: a fastball might travel at 95 mph from the pitcher's mound to home plate. Tennis players serve at speeds over 120 mph.

The measurement helps you connect speed, distance, and time. If your family is driving somewhere 120 miles away and you're going 60 mph, you know the trip will take about two hours.

Most other countries use kilometers per hour (kph) instead of mph, since they measure distance in kilometers rather than miles. One mph equals about 1.6 kph.