Race Time Prediction
Free Race Time Prediction calculator with clear step-by-step results.
About Race Time Prediction
Riegel's formula scales a race time by the distance ratio raised to ~1.06.
Formula
Formula
Prediction = known time × (target/known)^1.06
Worked example
With the default values below, Race Time Prediction returns Predicted Time (minutes) of 52.1. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Known distance (km)minimum 0.1 km
- 5 km
- Known time (minutes)minimum 1 min
- 25 min
- Target distance (km)minimum 0.1 km
- 10 km
Results
- Predicted Time (minutes)
- 52.1
- Predicted Pace (min/km)
- 5.21
- Time Multiplier
- 2.085
Step by step
- 1Values used
- 2Formula
- 3Predicted Time (minutes)= 52.1
- 4Predicted Pace (min/km)= 5.21
- 5Time Multiplier= 2.085
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- Estimates are general guidance — consult a healthcare professional for personal medical advice.
- This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Estimates are general guidance — consult a healthcare professional for personal medical advice.
Frequently Asked Questions
How does this calculator work?
Riegel's formula scales a race time by the distance ratio raised to ~1.06.
Why does this matter?
Assumes even pacing and comparable conditions.