Running Pace Calculator
Running Pace Calculator
Pace per kilometre and per mile from a distance and a finishing time, with the speed beside it. The headline is in seconds, because the calculator has no text type and cannot print a colon — the whole minutes and the remaining seconds are the two figures under it.
Pace from a distance and a time
Time ÷ distance10,000 m in 42 minutes 0 seconds
Formula
whole minutes = floor(round(pace) ÷ 60)
remaining seconds = round(pace) − 60 × whole minutes
pace per mile = pace per km × 1.609344
speed in km/h = 3600 ÷ pace in seconds per km
- pace is a reciprocal
- pace is time ÷ distance and speed is distance ÷ time, so they are inverses. Their product is a constant: a pace in seconds per kilometre multiplied by a speed in kilometres per hour is 3,600 exactly. Ten kilometres per hour is 360 seconds per kilometre, a pace of 6 minutes 0 seconds
- 1.609344
- metres in a mile, exactly. The yard is 0.9144 m by the 1959 definition recorded by NIST (Federal Register Notice 59-5442, 30 June 1959, making the inch exactly 25.4 mm), and a mile is 1,760 yards. The factor is definitional and does not belong to any governing body
- round before you split
- the minutes-and-seconds split is taken on round(pace), not on the raw value. Splitting 239.6 seconds before rounding gives 3 minutes and a seconds field of 59.6, which prints as 60; rounding first gives 4 minutes and 0 seconds. This is the one place a pace calculator goes wrong silently
- the distance is the measured one
- the pace is only as good as the distance. A road course carries a World Athletics course measurement certificate and a GPS watch does not; the two will disagree, and on a measured course the certificate is the authority
- no governing body publishes a pace
- this is arithmetic, not a regulation. The distances are regulated — the marathon is 42.195 km on World Athletics’ own discipline page, standardised in 1921 — but the division is just a division
Worked example
10,000 m in 42 minutes 0 seconds
42 minutes is 2,520 seconds, and 10,000 m is 10 km
2,520 ÷ 10 = 252.0 seconds per kilometre
round(252) ÷ 60 is 4 with 12 left over, so the pace is 4 minutes 12 seconds per kilometre
252 × 1.609344 = 405.55 seconds per mile, which rounds to 406 and splits as 6 minutes 46 seconds per mile
3,600 ÷ 252 = 14.286 km/h, and 252 × 14.286 = 3,600 exactly — the check that pace and speed really are reciprocals
Halve the time to 21 minutes and the pace halves to 126 seconds while the speed doubles to 28.571 km/h
Set either the distance or the time to zero and the panel shows nothing, because the division does not exist
The same pace in every unit a runner uses
| Seconds per km | Min:sec per km | Seconds per mile | Min:sec per mile | km/h | Per 400 m lap |
|---|---|---|---|---|---|
| 180.0 | 3:00 | 289.7 | 4:50 | 20.000 | 72.0 s |
| 240.0 | 4:00 | 386.2 | 6:26 | 15.000 | 96.0 s |
| 252.0 | 4:12 | 405.6 | 6:46 | 14.286 | 100.8 s |
| 300.0 | 5:00 | 482.8 | 8:03 | 12.000 | 120.0 s |
| 360.0 | 6:00 | 579.4 | 9:39 | 10.000 | 144.0 s |
| 420.0 | 7:00 | 676.1 | 11:16 | 8.571 | 168.0 s |
| 600.0 | 10:00 | 965.6 | 16:06 | 6.000 | 240.0 s |
Standard distances in metres, and what a pace turns into
| Distance | Metres | At 4:12 per km | Who fixes the distance |
|---|---|---|---|
| 1 mile | 1,609.344 | 6:45.6 | definitional: 1,760 × 0.9144 m |
| 5 km | 5,000 | 21:00.0 | a World Athletics standard road distance |
| 10 km | 10,000 | 42:00.0 | a World Athletics standard road distance |
| Half marathon | 21,097.5 | 1:28:36.3 | exactly half the marathon |
| Marathon | 42,195 | 2:57:12.5 | World Athletics: 42.195 km, standardised 1921 |
| 400 m lap | 400 | 1:40.8 | World Athletics Technical Rule 14.1 |
Pace is a reciprocal, and the colon is the hard part
This page is about athletics — track and field, and road running — whose competition rules, technical rules and scoring tables are published by World Athletics, the body that was the IAAF until 2019. Where a figure below belongs to a particular edition of those rules, the edition is named beside it, because World Athletics revises them and a number quoted without its edition will be wrong for somebody.
A pace is a time divided by a distance and nothing more. Forty-two minutes for 10 km is 2,520 seconds for 10 kilometres, which is 252 seconds for each one, which is 4 minutes 12 seconds. Doing it in that order — seconds first, minutes and seconds afterwards — is the only way to get it reliably right, and it is the order this page works in.
Pace and speed are reciprocals, not two scalings of one quantity. Speed is distance divided by time and pace is time divided by distance, so their product is fixed: a pace in seconds per kilometre multiplied by a speed in kilometres per hour is always 3,600. Ten kilometres per hour is 360 seconds per kilometre, which is a pace of 6 minutes 0 seconds, and doubling the speed halves the pace rather than doubling it. That is also why a single multiplicative unit ladder cannot hold both: a converter that offered minutes per kilometre and kilometres per hour in one list of factors would be converting between a quantity and its inverse.
A note on how a time is shown here. The calculator on this page is numeric: it has no text type, so it cannot print a colon and there is no “4:32” for it to show. The headline is therefore in seconds, and the whole minutes and the remaining seconds are given as separate figures beneath it — 272 seconds per kilometre, then 4 and 32. The split is taken on the rounded whole second rather than on the raw value, which matters more than it looks: a pace of 239.6 seconds per kilometre split before rounding reads “3 minutes and 60 seconds”, and rounding first makes it 4 minutes and 0 seconds.
Two things decide whether the answer means anything, and neither is the arithmetic. The first is the distance: a measured road course carries a World Athletics course measurement certificate and a watch does not, so the two will disagree and on a certified course the certificate wins. The second is how the time was taken. World Athletics records a fully automatic time to the next longer hundredth of a second for races up to and including 10,000 m and a hand time to the next longer tenth, always rounding away from the athlete, so a hand time and an electronic one are not the same measurement even when they read the same.
Where the line runs between this page and the health section: health owns the athlete’s body and this page owns the race. A figure derived from a person — aerobic capacity, a heart-rate zone, a body composition — is there, at the VO2 max calculator and the target heart-rate zones calculator. A figure derived from a clock and a distance is here. Nothing on this page prescribes a training pace or a heart rate, or makes any physiological claim.
For the other direction — a target pace turned into a finishing time and a set of splits — use the race split times calculator, which takes the pace and gives back the clock. For pace in a unit this page does not print, the pace unit converter holds the ladder. For what a result at one distance implies at another, the race time predictor does Riegel’s arithmetic and says what is wrong with it.
Frequently asked questions
How do you calculate running pace?
Divide the total time in seconds by the distance in kilometres. Ten kilometres in 42 minutes is 2,520 ÷ 10 = 252 seconds per kilometre, which is 4 minutes 12 seconds. For a mile, multiply the pace per kilometre by 1.609344.
Why is the answer in seconds instead of minutes and seconds?
Because the calculator is numeric and has no text type, so it cannot build the string “4:12”. The headline is the pace in seconds and the whole minutes and remaining seconds are the two figures under it. The split is done on the rounded whole second, which is why a pace of 239.6 seconds reads as 4 minutes 0 seconds and not 3 minutes 60.
What pace is 10 km/h?
Exactly 6 minutes 0 seconds per kilometre, or 360 seconds. Pace and speed are reciprocals: pace in seconds per kilometre multiplied by speed in km/h is always 3,600, so 3,600 ÷ 10 = 360. This is the easiest pair to check a calculator against.
Is pace the same thing as speed?
No — they are inverses. Speed is distance ÷ time and pace is time ÷ distance, so doubling one halves the other. A page that treats them as the same quantity scaled by a constant will be wrong in a way that looks plausible, which is why both are printed here with their product stated.
What pace do I need for a sub-three-hour marathon?
Three hours is 10,800 seconds and the marathon is 42.195 km, so 10,800 ÷ 42.195 = 255.9 seconds per kilometre, which is 4 minutes 16 seconds. Anything under that leaves room. Note that this is the pace the arithmetic requires and not advice about whether to attempt it.
Related calculators
References
- World Athletics. “Marathon” discipline page, worldathletics.org (read 12 Oct 2026; about 20,000 characters, much of it navigation). “Athletes run a distance of 26 miles and 385 yards (42.195km)”, and “this distance was standardised at 26 miles 385 yards (42.195km) in 1921”.
- World Athletics. Technical Rules (Book C, C2.1), copy read 12 Oct 2026 carrying amendments effective 1 January 2022; about 60,000 characters of readable text, truncated before the combined-events material. A time is recorded “to the next longer 0.01 second” for races up to and including 10,000m, and a hand time “to the next longer 0.1 second” — in both cases away from the athlete rather than to the nearest.
- National Institute of Standards and Technology. “SI Units — Length”, Office of Weights and Measures, nist.gov (read 12 Oct 2026). Records the 1958 agreement by which “a conference of English-speaking nations agreed to unify their standards of length and mass” and the 1959 Federal Register Notice 59-5442 of 30 June 1959 making the inch “exactly equivalent to 25.4 mm”, with a conversion equation giving 0.9144 m to the yard. The page does not state the mile in words, so the 1609.344 m used here is 1760 × 0.9144 m and is exact by that definition rather than quoted.