Calculate speed, distance or time — pick what you want to find
This free speed calculator solves for speed, distance or time. Choose what you want to find, enter the other two values in the units you prefer, and get the answer instantly. It works with kilometers, miles and meters, and with km/h, mph and m/s.
It is handy for planning road trips, working out running or cycling speed, and for physics homework.
The three quantities are linked by one simple relationship:
Examples:
Useful conversions: 1 mile = 1.60934 km, 1 m/s = 3.6 km/h, 1 knot = 1.852 km/h.
Divide the distance by the time. If you travel 100 km in 2 hours, your average speed is 100 ÷ 2 = 50 km/h. Choose "Find Speed" above, enter the distance and time, and the calculator does the rest.
Divide the distance by your speed. A 100 km trip at 60 km/h takes 100 ÷ 60 ≈ 1.67 hours, which is about 1 hour 40 minutes. Use the "Find Time" tab for this.
Divide km/h by 1.60934 to get mph. For example, 100 km/h is about 62.14 mph. To go from mph to km/h, multiply by 1.60934. The results panel shows these conversions for you.
Average speed is total distance divided by total time, including slow parts and stops. Instant speed is your speed at one exact moment, like the number on a car speedometer. This calculator finds average speed.
If you want your average speed for the whole trip, include the stops in the total time. If you want your moving speed only, enter just the time you were moving.
1 meter per second equals 3.6 km/h. To convert m/s to km/h, multiply by 3.6. To convert km/h to m/s, divide by 3.6.
Note: Results are average values and assume constant speed. Real travel time can change with traffic, weather and stops.