Running Pace Calculator
Pace, time or distance for any run, with splits, track laps and a printable pace band.
Splits
0.5–10%. The finish time stays the same: the first half is slower, the second half faster.
| Km | Split | Elapsed | Pace /km |
|---|
Treadmill speed to pace
—
| km/h | Pace /km | Pace /mile |
|---|
About the Running Pace Calculator
Pace is the time it takes to cover one kilometre or one mile; speed is its reciprocal. Enter any two of distance, time and pace and this calculator works out the third — for a 5 km parkrun, a half marathon, a 400 m track session or any custom distance in km, miles or metres.
It then lays out the run as splits every km, every mile or every 400 m lap, with an even pace or a negative split (a slower first half and a faster second half with the same finish time), converts treadmill speed in km/h or mph to pace, and prints a small pace band with the elapsed time you should see at each marker. Everything is calculated in your browser.
How to use it
- Choose what to work out: Find pace, Find time or Find distance. The field you are solving for disappears.
- Enter the distance (or pick a race such as 10 km or the marathon), the time in hours, minutes and seconds, and/or the pace per km or per mile.
- Read the pace per km and per mile, the speed, and the time for one 400 m lap.
- Under Splits, choose km, mile or 400 m lap, and Even pace or Negative split with how much faster the second half should be.
- Use Print pace band for a strip with your target elapsed times, or copy or download the splits. The treadmill box converts a belt speed to pace and can copy it into the calculator.
Examples
Pace 5:00 per km (8:03 per mile) · 12.0 km/h (7.46 mph) · 2:00.0 per 400 m lap
Pace 4:59 per km (8:01 per mile) · 42 one-km splits plus a final 195 m · halfway in 1:45:00 at even pace
First 5 km at 5:03 per km (25:15), last 5 km at 4:57 per km (24:45)
6:00 per km · 9:39 per mile
The formulas
- Pace = time ÷ distance. 25:00 for 5 km = 1,500 s ÷ 5 = 300 s = 5:00 per km.
- Time = distance × pace. 10 km at 6:00 per km = 1:00:00.
- Distance = time ÷ pace. 60 min at 8:00 per mile = 7.5 miles (12.07 km).
- Speed = distance ÷ time: 5 km in 25 min = 12 km/h. A treadmill speed converts to pace as 60 ÷ km/h minutes per km (10 km/h = 6:00 per km) or 60 ÷ mph minutes per mile.
- One mile is exactly 1,609.344 m, so a pace per mile is the pace per km × 1.609344.
Times are rounded to the nearest second for display (tenths for laps and short splits); the splits are worked out from the unrounded pace, so the elapsed times always add up to your finish time.
Even pace and negative splits
An even pace covers every km or mile in the same time. A negative split runs the second half faster than the first. Here, "second half 2% faster" means the second-half pace is 98% of the first-half pace while the finish time stays the same, so the first half is a little slower than your average: for 10 km in 50:00 that is 5:03 per km to halfway (25:15) and 4:57 per km after it (24:45). A split that crosses halfway mixes the two paces.
The calculator does not tell you which strategy is best — that depends on the course, the weather and your training. It shows exactly what each plan means in elapsed times, so you can check yourself during the race.
Race distances, laps and course measurement
The presets are the track events from 400 m to 3000 m and the standard road distances in the World Athletics Technical Rules (Rule 55): road mile (1,609.344 m), 5 km, 10 km, 15 km, 10 miles, 20 km, half marathon (21.0975 km), 25 km, 30 km, marathon (42.195 km), 50 km and 100 km.
A standard track is 400 m in lane 1 (Technical Rule 14, track measurements), so a mile is 4 laps plus 9.344 m and 1500 m is 3¾ laps; outer lanes are longer, which is why lap times here assume lane 1. Road courses are measured along the shortest possible route an athlete could run, must not be shorter than the official distance, and World Athletics recommends building in a 0.1% "short course prevention factor" (each km laid out as 1,001 m) (Technical Rule 55). A GPS watch that records the line you actually ran, around corners and other runners, therefore usually shows a little more than the race distance — run your pace band by the course markers, not by the watch.
Treadmill pace
The belt speed converts exactly to pace, but running indoors has no air resistance. In a study of nine trained runners, a 1% treadmill incline matched the energy cost of level outdoor running for runs of about 5 minutes at 10.5–18 km/h (Jones & Doust, J Sports Sci 14:321-7). The pace shown here is the belt speed itself; it does not add that correction.
Sources
- World Athletics, Book C2.1 Technical Rules — Rule 14 (track measurements: the 400 m standard oval track) and Rule 55 (road races: standard distances and course measurement)
- Jones AM, Doust JH. A 1% treadmill grade most accurately reflects the energetic cost of outdoor running. J Sports Sci 14(4):321-7
Limitations
- Splits assume you hold the planned pace on every section; hills, wind, crowded starts and drink stations change real splits.
- Lap times are for lane 1 of a 400 m track; lap tables are offered for distances up to 10,000 m (25 laps).
- Paces from 1:00 to 60:00 per km and distances up to 1,000 km are accepted; a pace faster than 2:00 per km is flagged so you can check the units.
- This is a pacing calculator, not a training plan or a prediction of what time you can run.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
How do I calculate my running pace?
Divide your time by the distance. 50 minutes for 10 km is 5:00 per km, which is 8:03 per mile (10 km is 6.21 miles). Enter the distance and time with Find pace selected and the calculator does it in both units.
What pace do I need for a sub-2-hour half marathon?
Faster than 5:41 per km (9:09 per mile): 2:00:00 ÷ 21.0975 km = 5:41.3 per km. Enter 21.0975 km (or pick Half marathon) and 2:00:00 to see the km-by-km elapsed times, then print them as a pace band.
What is a negative split?
Running the second half of a race faster than the first. With Negative split selected, choose how much faster the second half should be (for example 2%); the calculator keeps your finish time and shows how much slower the first half has to be.
How many laps of a track is a mile, 5 km or 10 km?
In lane 1 of a 400 m track: a mile is 4 laps plus 9.34 m, 5,000 m is 12½ laps and 10,000 m is 25 laps. Choose 400 m lap under Splits to see each lap time.
Why does my GPS watch show more than the race distance?
Road races are measured along the shortest possible route, and World Athletics recommends building in an extra 0.1% so a course is never short. Few runners hold that line exactly, and GPS adds its own error, so watches usually read a little long. Pace yourself on the course markers.
How do I convert treadmill speed to pace?
Pace in minutes per km = 60 ÷ speed in km/h; pace in minutes per mile = 60 ÷ speed in mph. 12 km/h is 5:00 per km, 6 mph is 10:00 per mile. The treadmill box does this and has a quick table from 6 to 20 km/h or 3 to 12 mph.