Running pace and speed calculator
Last updated: April 28, 2026
Enter the distance covered and your time: instantly get your pace per kilometre, your speed in km/h and the projection of your time on standard distances (5K, 10K, half-marathon, marathon).
Useful to lock training paces, compare two runs, or estimate a target time before a race.
Your pace
/km
/mi
Speed
km/h
mph
Projection on standard distances
If you maintain this exact pace.
| Distance | Estimated time |
|---|---|
| 5 km | |
| 10 km | |
| 21,1 km | |
| 42,2 km |
Linear projection: in reality pace slows slightly on longer distances. For a precise 10K, half or marathon estimate, use the Riegel calculator.
The formulas used
- Pace (sec/km) = total time (sec) ÷ distance (km).
- Speed (km/h) = distance (km) ÷ time (hours).
- Mile conversion: pace /mile = pace /km × 1.609.
How to use it
- After a session: enter distance and time to know your exact pace.
- Before a race: enter target pace and distance to verify expected finish time.
- To set up intervals: convert target pace to time per 400 m, 800 m or 1,000 m.
Linear projection vs Riegel
Projections shown are linear: assumes you maintain exactly the same pace on longer distances. Real-world, pace slows slightly as distance grows.
For more realistic projections from a known time, use the Riegel calculator.
FAQ
What is the difference between pace and speed?
Same thing, expressed differently. Pace in min/km (faster = smaller number). Speed in km/h (faster = bigger number). 5:00 /km equals 12 km/h.
Why do projections differ from my real race time?
Linear projections do not account for fatigue, elevation, wind or distance experience. Reliable within ±10% for trained runners.
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