Speed Calculator
Work out speed, distance, or time from the other two, in your units.
Runs in your browser — nothing is sent or saved.
How to use the speed calculator
- Choose what to solve for: speed, distance, or time.
- Enter the other two values, each in your chosen unit.
- Read the answer, shown in several units.
- Copy the link to save or share it.
Speed, distance, and time
These three quantities are tied together by one relationship: speed equals distance divided by time. Rearranged, distance equals speed times time, and time equals distance divided by speed. This speed calculator lets you solve for any of the three from the other two, a distance time speed solver that answers how fast, how far, or how long in one place, and doubles as an mph calculator. Each field has its own unit, so you can mix miles with hours or metres with seconds.
Average speed
The speed this tool gives is an average over the whole trip, not your speed at any single moment. If you drive 100 miles in 2 hours, your average speed is 50 miles per hour, even though you sped up and slowed down along the way. Average speed is what matters for planning a journey or checking a pace, and it is what distance divided by time always gives.
Mixing units
Because distance, time, and speed each have a unit selector, you never have to convert by hand. Enter kilometres and hours to get km/h, or metres and seconds to get m/s, and the result is also shown in the other common speed units. That makes it easy to compare a running pace in minutes per kilometre with a car speed in miles per hour.
A worked example
A cyclist covers 30 kilometres in 1 hour 30 minutes, which is 1.5 hours. Speed is 30 divided by 1.5, which is 20 kilometres per hour, or about 12.4 miles per hour.
FAQ
How do I calculate average speed?
Divide the distance by the time. For 100 miles in 2 hours, the average speed is 50 miles per hour. The tool shows the result in mph, km/h, and m/s.
How do I find distance from speed and time?
Multiply speed by time. At 60 mph for 3 hours you cover 180 miles. Choose Distance and enter the speed and time.
How do I find time from speed and distance?
Divide distance by speed. To cover 150 km at 75 km/h takes 2 hours. Choose Time and enter the speed and distance.
Can I mix units like miles and minutes?
Yes. Each value has its own unit selector, so you can enter distance and time in whatever units you have, and the tool converts for you.
Is my information private?
Yes. Everything is calculated in your browser and nothing you enter is uploaded or saved.