Running Pace Calculator
Work out your pace, finish time, or distance from the other two, with speed and even splits.
What is running pace?
Pace is how long it takes you to cover one kilometer or one mile, written as minutes and seconds — for example 5:30 per km. Runners use pace rather than speed because it maps directly onto a watch and a race plan: if you know your pace, you know your finish time for any distance, and vice versa.
How pace, time, and distance are calculated
Pace, finish time, and distance are linked, so any two give you the third:
Pace = time ÷ distance · Time = pace × distance · Distance = time ÷ pace
Speed is the inverse of pace: a 5:00 per km pace is 12 km/h. One mile is exactly 1.609344 km. Official race distances are 5 km, 10 km, 21.0975 km for a half marathon (13.1 miles), and 42.195 km for a marathon (26.2 miles).
How to use this calculator
Choose what you want to calculate — pace, finish time, or distance — and whether you think in kilometers or miles. Enter the other two values (use the race presets for standard distances) and press the calculate button. You'll see pace in both units, finish time, distance, speed, and a table of elapsed times at every kilometer or mile so you can check progress during a race.
Using your splits
The split table assumes a perfectly even pace. Many runners aim for even or slightly negative splits — running the second half a little faster than the first — because starting too fast tends to cost more time later than it saves early. Write down a few checkpoint times, or set your watch's pace alert to your target range.
Limitations
A pace calculator is simple arithmetic, not a race predictor. Your pace at 5K won't hold for a marathon, and hills, wind, heat, crowds, and fatigue all slow real-world running. GPS watches also tend to measure race courses slightly long because runners rarely follow the exact measured line. Pair your pace targets with effort — the Heart Rate Zone Calculator can help you keep easy runs easy.
Read the science
- Pacing Strategy: The Science of Running Your Best Race →
Why even pacing beats a fast start, what world records reveal about how the best runners spread their effort, how the marathon got its odd distance, and how to plan your own splits.
References
The formulas and figures on this page come from these sources. Our Editorial Policy explains how they're chosen and checked.
- 1 mile = 1.609344 km: Thompson, A., & Taylor, B. N. (2008). Guide for the use of the International System of Units (SI) (NIST Special Publication 811). National Institute of Standards and Technology. Link
- Marathon distance (42.195 km): World Athletics. (2008, May 31). Queen Elizabeth marks 1908 London Olympics and centenary of “classic marathon distance”. Link
- How race courses are measured: Association of International Marathons and Distance Races. The measurement of road race courses (2nd ed.). AIMS / World Athletics. Link
- Pacing in marathon world records: Díaz, J. J., Fernández-Ozcorta, E. J., & Santos-Concejero, J. (2018). The influence of pacing strategy on marathon world records. European Journal of Sport Science, 18(6), 781–786. doi:10.1080/17461391.2018.1450899