Speed, distance and time calculator
Choose what you want to find, fill in the other two, and get the answer in every unit, with your pace per kilometer and per mile.
Sealed on this device
Runs in your browser. Nothing is uploaded.
Sealed
Your numbers
Speed = distance ÷ time
Result
- Speed
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- Pace per kilometer
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- Pace per mile
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Race finish times at this speed
| Race | Finish time |
|---|---|
| 5 km | — |
| 10 km | — |
| Half marathon | — |
| Marathon | — |
Finish times appear here once a speed is known.
How it works
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Choose what to find
Pick speed, distance or time. The calculator asks only for the two values it needs.
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Fill in the other two
Enter the distance in kilometers, miles, meters or nautical miles, the time in hours, minutes and seconds, or a speed in km/h, mph, m/s or knots.
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Read your result and pace
See the answer in every unit, your pace per kilometer and per mile, and the finish times you would reach over 5 km, 10 km, a half marathon and a marathon.
Frequently asked questions
How do you calculate speed?
Divide the distance by the time. For example, 150 km in 2 hours is 150 ÷ 2 = 75 km/h. To find a distance, multiply speed by time; to find a time, divide distance by speed.
How do I convert km/h to mph?
Divide by 1.609344, because one mile is exactly 1.609344 km. So 100 km/h is about 62.14 mph. To go from mph to km/h, multiply by 1.609344.
How is running pace calculated?
Pace is the time it takes to cover one kilometer or one mile: divide 60 by your speed in km/h to get minutes per kilometer. At 12 km/h, the pace is 5:00 per kilometer.
How long is a half marathon and a marathon?
A marathon is 42.195 km (about 26.2 miles) and a half marathon is half that, 21.0975 km (about 13.1 miles). The finish times shown assume you hold the same speed for the whole race.
What is a knot?
A knot is one nautical mile per hour, used at sea and in aviation. A nautical mile is exactly 1,852 meters, so 1 knot is 1.852 km/h, or about 1.15 mph.
Are my numbers sent anywhere?
No. Every calculation happens in your browser, and nothing is stored once you close the page.