Lunia · Free tools
Race Time Predictor
Find your average race pace and a finish-time projection for another distance.
Your details
Runs entirely in your browser. Nothing you type is sent anywhere or saved.
Your result
Ready to calculate
Enter your details, then calculate to see your result here.
How this calculator works
Average pace is elapsed time ÷ race distance. Target finish time is pace × target distance. This constant-pace model answers what the same pace would produce, rather than predicting your endurance.
A worked example
Distance: 5 · Distance unit: Kilometres · Finish time: minutes: 30 · Finish time: seconds: 0 · Target distance (km): 21.0975
- Pace per kilometre
- 6:00 /km
- Pace per mile
- 9:39 /mi
- Average speed
- 10 km/h
- Finish at the same pace over 21.098 km
- 2:06:35
These are illustrative inputs, not personal recommendations.
Common questions
How is this different from the marathon predictor?
This tool keeps pace constant. The marathon predictor uses the Riegel exponent to model slowing as distance increases.
How should I use the result?
Use a recent race on comparable terrain. The number is a pacing calculation, not a promise about a future race.
Sources & method references
Formula-based results are estimates, not individual medical advice.