Sport & running
How do you calculate race finish time from pace?
Enter distance and pace to get your finish time, or distance and goal time to get the required pace.
Quick answer
Finish time equals pace in seconds per km multiplied by distance in km. Running 10 km at 5:30/km (330 sec/km): 330 × 10 = 3,300 seconds = 55 minutes. To find the pace needed for a goal time, divide total seconds by distance: 50 minutes (3,000 sec) over 10 km = 5:00/km.
Estimated finish time
55′ 00″
How it works
| Race | Goal | Pace per km | Pace per mile |
|---|---|---|---|
| 5K | sub 20 | 4:00 /km | 6:26 /mi |
| 5K | sub 25 | 5:00 /km | 8:02 /mi |
| 5K | sub 30 | 6:00 /km | 9:39 /mi |
| 10K | sub 45 | 4:30 /km | 7:14 /mi |
| 10K | sub 50 | 5:00 /km | 8:02 /mi |
| 10K | sub 60 | 6:00 /km | 9:39 /mi |
| Half | sub 1:45 | 4:58 /km | 8:00 /mi |
| Half | sub 2:00 | 5:41 /km | 9:09 /mi |
| Half | sub 2:30 | 7:06 /km | 11:26 /mi |
| Marathon | sub 3:30 | 4:58 /km | 8:00 /mi |
| Marathon | sub 4:00 | 5:41 /km | 9:09 /mi |
| Marathon | sub 4:30 | 6:23 /km | 10:17 /mi |
| Marathon | sub 5:00 | 7:06 /km | 11:26 /mi |
Two goals share the same pace, and it is the most useful coincidence in road running: a 2-hour half and a 4-hour marathon both need 5:41 /km (9:09 /mile). If you can hold that for 21 km you already own the marathon pace — what is missing is not speed but the ability to keep it for twice the distance. The same pairing repeats one step up: sub-1:45 half and sub-3:30 marathon both sit at 4:58 /km, a round 8:00 /mile.
The calculator works both ways — enter distance and pace for finish time, or distance and goal time for required pace. Average speed in km/h is simply 3600 divided by pace seconds per km. Write your goal pace on a running gel belt or watch screen for race morning — mental math at km 30 is unreliable.
Add 2–5% buffer for crowded starts, aid stations and course turns. A flat 10K at 5:00/km might need 5:05/km on a hilly half. Racing shoes save seconds per km but do not fix a pace you have not trained at. Training guidance only, not medical advice.
Projecting from one distance to another is not multiplication. Doubling the distance costs more than double the time, and the standard correction is Riegel's: new time = old time × (new distance ÷ old distance) raised to the power 1.06 — so a 50-minute 10 km predicts a half marathon around 1 hour 44, not 1 hour 40. The exponent gets worse, not better, if your longest training run is far shorter than the race: the formula assumes you have the endurance base for the new distance, and it is the base, not the speed, that decides the last five kilometres.
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Frequently asked questions
How long does a marathon take at 5:00/km?+
A marathon is 42.195 km. At 5:00/km (300 sec/km): 300 × 42.195 = 12,659 seconds ≈ 3 hours 31 minutes. Most recreational runners target 4–5 hours; elites run under 2:10. Add 3–5 minutes for typical big-city corral delays in the first 2 km.
Should I pace evenly or start faster?+
Even pacing (or a slight negative split — second half faster) produces the best times for most runners. Starting too fast burns glycogen early and leads to a painful final third. Use this calculator to set a realistic per-km target before race day — write splits on your arm or watch, not just the average.
How accurate are race time estimates?+
They assume you hold the entered pace for the full distance — no hills, wind, heat or fading. Add 5–15 seconds per km for hilly courses or hot weather. Training at goal pace over shorter distances validates whether the estimate is realistic — a 10K time trial at goal half-marathon pace is a strong signal.
What is negative split pacing?+
Running the second half of a race faster than the first. Example: first 10K in 28 minutes, second 10K in 27 minutes for a 55-minute finish. It is the strategy most world records use because it avoids early overexertion. On hilly courses, negative split often means easing on climbs and pushing descents.
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