Calculate Pace
Enter your distance and finish time. Pace = Time ÷ Distance. Example: 50:00 for 10 km = 5:00 min/km.
Running Pace & Race Time Predictor
Fast Online Running Pace Calculator
100% Free, Browser-Based Running Pace, Time & Distance Calculator.
Running pace, time and distance calculator
Your Pace
/km
10 km in 50:00
Pace / km
5:00
Pace / mile
8:03
Speed
12.00 km/h
Speed
7.46 mph
Distance
10.00 km
6.21 mi
Total Time
50:00
3,000 seconds
Split Times per km
| Split | Lap Time | Cumulative |
|---|
Estimated Race Finishing Times
Even pace = same pace held for the whole race. Riegel = fatigue-adjusted prediction (T₂ = T₁ × (D₂/D₁)1.06).
| Race | Even Pace | Riegel |
|---|
How the Running Pace Calculator Works
Calculate Time
Enter target pace and race distance. Time = Pace × Distance. Example: 5:41/km × 42.195 km ≈ 3:59:50.
Calculate Distance
Enter run time and pace. Distance = Time ÷ Pace. Example: 1 hour at 6:00/km = 10 km.
Popular Race Goal Paces
| Goal | Pace / km | Pace / mile | Speed |
|---|---|---|---|
| Sub-20 min 5K | 4:00 | 6:26 | 15.0 km/h |
| Sub-25 min 5K | 5:00 | 8:03 | 12.0 km/h |
| Sub-50 min 10K | 5:00 | 8:03 | 12.0 km/h |
| Sub-2 hour Half Marathon | 5:41 | 9:09 | 10.5 km/h |
| Sub-3 hour Marathon | 4:15 | 6:51 | 14.1 km/h |
| Sub-4 hour Marathon | 5:41 | 9:09 | 10.5 km/h |
| Sub-5 hour Marathon | 7:06 | 11:26 | 8.4 km/h |
Why Use Running Pace Calculator?
- ✓Instant results — every keystroke recalculates pace, time, speed and splits with zero page reloads.
- ✓100% private — all math runs locally in your browser; nothing is uploaded or stored on a server.
- ✓Metric & imperial — switch between km/min per km and miles/min per mile at any time.
- ✓Race-ready planning — copy split tables for pace bands and predict 5K to 50K finish times.
Frequently Asked Questions
How to calculate running pace per km or mile?
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Divide your total running time by the distance covered. For example, 50 minutes over 10 km is 50 ÷ 10 = 5:00 per km. For pace per mile, divide by the distance in miles instead (10 km = 6.214 mi), giving 8:03 per mile. Use the Calculate Pace tab above to do this instantly.
What pace is needed to run a sub-4 hour marathon?
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A marathon is 42.195 km (26.2 miles). To finish under 4:00:00 you must average faster than 5:41 per km or 9:09 per mile. Many runners aim for about 5:35/km (9:00/mi) to leave a buffer for aid stations, crowded starts and late-race fatigue.
How to use split tables for race pacing?
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A split table shows the cumulative time you should see on your watch at every kilometer or mile marker. Compare your actual time at each marker with the table: if you are ahead, ease off slightly to save energy; if you are behind, close the gap gradually rather than surging. Click Copy Split Table to paste it into notes, print a pace band, or plan interval workouts.
How do I convert running pace to speed?
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Speed = 60 ÷ pace (in minutes). A 5:00 min/km pace equals 12 km/h; an 8:00 min/mile pace equals 7.5 mph. Running Pace Calculator works as a running speed converter, showing pace and speed in both metric and imperial units automatically — handy for treadmill settings.
How accurate are the race time predictions?
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The Even Pace column multiplies your pace by each race distance. The Riegel column uses Pete Riegel's formula T₂ = T₁ × (D₂ / D₁)1.06, which accounts for slowing down over longer distances. Predictions are most reliable between nearby distances and assume you have trained appropriately for the longer race.
Is Running Pace Calculator free and private?
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Yes. Running Pace Calculator is completely free, needs no sign-up, and runs 100% in your browser. Your times and distances never leave your device.