Running Pace Calculator
A 5K in 25:00 works out to 5:00 per kilometer and 12.00 km/h. This running pace calculator turns one finished run into the numbers runners actually use when they plan workouts, compare race efforts, or set treadmill targets. Enter your distance and total time to get average pace, average speed, and a clean time summary. If your distance is in miles, the pace is per mile. If your distance is in kilometers, the pace is per kilometer. That makes the result useful for everything from a one-mile time trial to a marathon check-in.
Quick answer
Pace tells you how long one mile or one kilometer took at your average effort.
What this tells you
- •Pace tells you how long one mile or one kilometer took at your average effort.
- •Speed tells you how much distance you covered in one hour at that same average effort.
- •The tool does not guess your unit. A distance of 10 means 10 miles if you think in miles and 10 kilometers if you think in kilometers.
- •Average pace is a summary of the whole run. It does not show whether you started too fast, faded late, or ran negative splits.
- •This is most useful when you want a simple benchmark you can repeat after future runs.
How to Use
- 1Enter the total distance you covered. Use 3.1069 for a 5K in miles, 5 for a 5K in kilometers, 13.1094 for a half marathon in miles, or 42.195 for a marathon in kilometers.
- 2Enter your full finishing time using hours, minutes, and seconds. For a short run, leave hours at 0. For a long race, fill all three fields.
- 3Keep your distance unit consistent with how you want to read the answer. A mile-based distance returns pace per mile. A kilometer-based distance returns pace per kilometer.
- 4Click calculate to see your average pace, average speed, and total time in one place.
- 5Use the pace result to plan workouts. Many runners use it to set treadmill pace, estimate repeat targets, or compare recent race efforts over the same distance.
- 6If you want to compare two race results fairly, run both in the same unit first so you are not mentally converting one pace format to another.
How It Works
Formula
Pace per unit = total time / distance
Speed per hour = distance / total time in hoursThe calculator first converts your entered hours, minutes, and seconds into one total time. It then divides that time by distance to get pace per unit distance and divides distance by total hours to get average speed. Pace and speed describe the same run from opposite directions.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
5K in 25 minutes
This is a common benchmark for newer racers because it lands on a clean 5-minute kilometer pace. It is also easy to use for treadmill work since 12 km/h matches the same effort.
Half marathon under 1 hour 52 minutes
That average pace is useful when you want to build race-week pacing bands. If the opening miles come in much faster than 8:33, there is a good chance the finish will get expensive.
Marathon training long run
Long-run pace usually sits slower than race pace. This kind of result helps you check whether an easy run stayed easy instead of drifting into moderate effort.
Four-hour marathon goal at the exact distance
Marcus wants to break 4 hours in his first marathon and needs a number to set on his watch. Entering the official 42.195 km and 4:00:00 gives 240 / 42.195 = 5.688 minutes, shown as 5:41 per kilometer, and 42.195 / 4 = 10.55 km/h. In miles, entering 26.2188 returns 9:09 per mile and 6.55 mph, while the rounded 26.2 returns 9:10. Because the course is measured along the shortest legal line and he will not hold it through every turn, he aims a few seconds per kilometer under 5:41 so the extra distance does not cost him the goal.
Running pace chart for common race finish times
Pace per kilometer, pace per mile, and average speed for goal times at the mile, 5K, 10K, half marathon, and marathon. A half marathon in a given time has the same pace as a marathon in twice that time, which is why those rows match.
| Race | Finish time | Pace per km | Pace per mile | km/h | mph |
|---|---|---|---|---|---|
| 1 mile | 6:00 | 3:44 | 6:00 | 16.09 | 10.00 |
| 1 mile | 8:00 | 4:58 | 8:00 | 12.07 | 7.50 |
| 1 mile | 10:00 | 6:13 | 10:00 | 9.66 | 6.00 |
| 5K | 20:00 | 4:00 | 6:26 | 15.00 | 9.32 |
| 5K | 25:00 | 5:00 | 8:03 | 12.00 | 7.46 |
| 5K | 30:00 | 6:00 | 9:39 | 10.00 | 6.21 |
| 10K | 45:00 | 4:30 | 7:15 | 13.33 | 8.28 |
| 10K | 55:00 | 5:30 | 8:51 | 10.91 | 6.78 |
| Half marathon | 1:45:00 | 4:59 | 8:01 | 12.06 | 7.49 |
| Half marathon | 2:00:00 | 5:41 | 9:09 | 10.55 | 6.55 |
| Half marathon | 2:30:00 | 7:07 | 11:27 | 8.44 | 5.24 |
| Marathon | 3:00:00 | 4:16 | 6:52 | 14.06 | 8.74 |
| Marathon | 3:30:00 | 4:59 | 8:01 | 12.06 | 7.49 |
| Marathon | 4:00:00 | 5:41 | 9:09 | 10.55 | 6.55 |
| Marathon | 4:30:00 | 6:24 | 10:18 | 9.38 | 5.83 |
Computed with the formula above by entering each finish time twice, once with the distance in kilometers (1.609344, 5, 10, 21.0975, 42.195) and once in miles (1, 3.1069, 6.2137, 13.1094, 26.2188, the kilometer distance divided by 1.609344 and rounded to four decimals, which gives the same result as the unrounded value). Pace is rounded to the nearest second and speed to two decimals, as the tool rounds them. The mile is exactly 1,609.344 m (NIST SP 811, Appendix B), the marathon is 42.195 km under World Athletics road race rules, and the half marathon is half of that.
Pace, speed, and the exact race distances
Pace and speed are the same number turned upside down. Pace is time divided by distance, so 25 minutes over 5 km is 5:00 per kilometer. Speed is distance divided by time in hours, so the same run is 5 / (25 / 60) = 12.00 km/h, which is also 60 divided by the pace in decimal minutes. Finish time runs the other way: pace times distance. A 9:09 mile held for 26.2188 miles comes to 239.9 minutes, a few seconds under 4 hours, and the small gap is the rounding of pace to the whole second. Average pace still hides the shape of a run. Two runners with the same 10K average can get there with even splits or with a fast start and a slow finish, so check your splits when pacing strategy matters.
Per-mile and per-kilometer pace differ by an exact factor. The international mile is 1,609.344 meters, because the international yard is exactly 0.9144 m and a mile is 1,760 yards (NIST SP 811, Appendix B). Multiply a per-kilometer pace by 1.609344 to get the per-mile pace, so 5:00 per km is 8:03 per mile. World Athletics road race rules set the marathon at 42.195 km, which is 26.2188 miles, and the half marathon at 21.0975 km, or 13.1094 miles. A 5K is 3.1069 miles. Rounding those to 26.2, 13.1, and 3.1 can move the per-mile pace by a second: a 25:00 5K reads 8:03 per mile at 3.1069 and 8:04 at 3.1, and a 4:00:00 marathon reads 9:09 at 26.2188 and 9:10 at 26.2.
Certified courses run slightly long on purpose. Road courses are measured along the shortest route a runner could legally take, and measurers apply a short course prevention factor of 1.001, which adds about 42 m to a marathon so the course is never short. Few runners hold that line through every corner, and a GPS watch traces the path you actually ran, so watch distance usually reads long and watch pace reads fast. If your watch logs 26.5 miles for a 4:00:00 marathon, it reports 9:03 per mile, while the certified 26.2188 miles gives 9:09. Enter the official distance when you compare races, and the watch distance when you want to know how fast you actually moved.
This tool reports the pace you ran. It does not predict a time at another distance. Most race predictors use the power law Peter Riegel described in American Scientist in 1981, fit to world-record times and usually written T2 = T1 x (D2 / D1)^1.06, for efforts lasting roughly 3.5 to 230 minutes. From a 25:00 5K it predicts 52:07 for 10K, 1:55:00 for the half marathon, and 3:59:47 for the marathon. Treat the long end with care. Vickers and Vertosick surveyed 2,303 recreational runners in BMC Sports Science, Medicine and Rehabilitation in 2016 and found the formula well calibrated up to the half marathon but at least 10 minutes too fast at the marathon for half of them. A model that added weekly training mileage to a previous race time predicted marathon times better.
Common mistakes
- Entering 5 for a 5K and then reading the pace as minutes per mile. A distance of 5 only means 5 miles if you intended miles.
- Leaving hours, minutes, and seconds all at zero. Without total time, pace and speed are meaningless.
- Comparing a kilometer-based run to a mile-based run without converting one first. The raw pace numbers are not directly comparable.
- Using average pace to judge interval workouts with rest breaks included. For repeats, calculate each work interval separately when you need precise training targets.
- Treating one run as a permanent fitness verdict. Pace depends on terrain, weather, fatigue, and pacing decisions as much as raw fitness.
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