This speed calculator finds average speed, distance or travel time from the other two values. It works in miles and mph or kilometers and km/h, and converts the speed to m/s and knots.
Speed, distance and time formulas
Speed = distance ÷ time, distance = speed × time, time = distance ÷ speed
Worked example
Driving 100 miles in 1 hour 30 minutes is an average speed of 100 ÷ 1.5 = 66.67 mph, or about 107.29 km/h.
Frequently asked questions
Is this average speed or top speed?
Average speed: total distance divided by total time, including slower stretches and stops if you count them in the time.
How do I convert mph to km/h?
Multiply by 1.609344. To go from km/h to m/s, divide by 3.6. For running splits, use the pace calculator.