Running Pace Calculator On-device
Solve pace, time or distance — with a split table and a race-time predictor.
Split times
Race-time predictor (Riegel)
Riegel's formula (T2 = T1 × (D2 ÷ D1)^1.06) was derived from race results lasting roughly 3.5–230 minutes; accuracy degrades as the gap between the two distances grows.
Estimates for training reference only — not medical or coaching advice.
Free running pace calculator: solve pace, time or distance from the other two, see split times at any interval, and predict race times with Riegel's formula. Works entirely on your device.
About this tool
What you provide
- Any two of pace, time and distance, in kilometres or miles
- A recent race distance and time, for the race-time predictor
What you get
- The third value, plus average speed in km/h or mph
- A cumulative split table at the interval you choose
- A predicted time for another distance using Riegel's formula
Limits
- Riegel's formula was derived from race results lasting roughly 3.5–230 minutes, and accuracy degrades as the gap between the two distances grows.
- Estimates for training reference only — not medical or coaching advice.
How to use it
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Choose km or mi
Press km or mi; every distance, pace and speed figure on the page follows that unit.
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Choose what to solve for
Press Pace, Time or Distance — the tool then asks for the other two values.
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Enter the two known values
Fill in the distance, the time in hours, minutes and seconds, or the pace in minutes and seconds per unit; the answer and your average speed appear as you type.
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Set the split interval
Under Split times, enter how often to split to get a table of cumulative times at each interval.
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Predict a race time
In the Riegel section enter a recent race distance and time, pick 5K, 10K, half marathon, marathon or a custom target, and read the predicted time and the pace it implies.
Frequently asked questions
How do I calculate my running pace?
Enter any two of pace, time, or distance and the tool solves for the third, and it also shows a split table and predicts your race time for other distances.
Does it give a split table for races?
Yes, alongside solving pace, time, or distance, it shows a split table and a race-time predictor.
Is the running pace calculator free?
Yes, it's free and runs on your device with no signup.