Pace Calculator
Running pace, finish time or distance, with split tables. Runs in your browser.
About this pace calculator
This pace calculator works out your running pace from a distance and time, your finish time from a pace, or how far you will go in a set time. It is for runners planning a race, a training run or a goal time, in kilometres or miles.
Tap a preset for 1 mile, 5K, 10K, half marathon or marathon. You get pace per km and per mile, speed in km/h and mph, a 400 m lap time, a split table you can copy as CSV, and predicted times for other race distances.
Times accept the formats you would actually type: 25:00, 1:45:30, or even 1h20m.
Features
Solve for any of the three
Pace from distance and time, time from distance and pace, or distance from time and pace.
Race presets
1 mile, 5K, 10K, half marathon (21.0975 km) and marathon (42.195 km), in km or miles.
Split tables
Every km, every mile, every 400 m lap, every 5 km or each half, with split time, elapsed time and pace. Copy the table as CSV for a pace band or spreadsheet.
Negative splits
Set the second half up to 10% faster than the first. The total time stays the same, so you see exactly how to share out the effort.
Race predictions
Riegel's formula turns your result into estimated times for 1500 m, 1 mile, 5K, 10K, half and full marathon.
Unit switch that keeps your numbers
Going from km to miles converts your distance and pace instead of clearing them.
How to use the pace calculator
- 1Choose what to work out: pace, time or distance, in km or miles.
- 2Enter the other two values or tap a race preset like 5K or marathon.
- 3Read the result, speed, split table and predicted times for other races.
When to use it
Picking a goal pace
Want a sub-2 hour half marathon? Choose Time, enter the half preset and try paces until the finish time drops below 2:00:00. The answer is about 5:41 per km.
Making a pace band
Pick 'every km' or 'every mile', copy the CSV and print it, or write the elapsed times on your arm.
Logging a run
Your watch says 7.3 km in 41:20. Enter both to get the pace and speed. For timing intervals you can use the online stopwatch.
Converting a treadmill speed
Treadmills show km/h or mph. Set Distance mode with 60:00 and your pace to compare, or read the speed straight off the result.
How do you calculate running pace?
Pace is time divided by distance. A 10K in 55:00 is 55 ÷ 10 = 5.5 minutes per km, which is 5:30 per km. Because pace is written in minutes and seconds, 0.5 of a minute is 30 seconds, not 50.
To go the other way, multiply. At 5:30 per km a half marathon takes 5.5 × 21.0975 = 116 minutes, or 1:56:02. For distance, divide the time by the pace.
Speed is the flip side of pace: 60 ÷ pace in minutes. 5:30 per km is 60 ÷ 5.5 = 10.9 km/h. A mile is exactly 1.609344 km, so 5:30 per km is about 8:51 per mile. If you need other unit swaps, the unit converter handles them.
What pace do I need for common race goals?
Even-pace targets for popular goal times, rounded to the second:
- 5K in 25:00: 5:00 per km, 8:03 per mile
- 10K in 50:00: 5:00 per km, 8:03 per mile
- Half marathon in 2:00:00: 5:41 per km, 9:09 per mile
- Marathon in 4:00:00: 5:41 per km, 9:09 per mile
- Marathon in 3:30:00: 4:59 per km, 8:01 per mile
How does the race time predictor work?
It uses Peter Riegel's 1981 formula: T2 = T1 × (D2 ÷ D1)^1.06. The exponent above 1 means you slow down a little as the distance grows. A 25:00 5K predicts about 52:07 for 10K and 3:59:47 for a marathon.
The prediction assumes you have trained for the longer race. For the marathon especially, most runners come in slower than Riegel says unless their weekly mileage is high. Treat long-range predictions as a best case.
What is a negative split?
Running the second half faster than the first. Many coaches recommend it because going out too fast burns energy you need later. With a 2% negative split on a 50:00 10K, your first 5 km takes about 25:15 and the second about 24:45.
Why use Mavros
| Mavros | Typical upload sites | |
|---|---|---|
| Split table | km, mile, 400 m, 5 km or halves, with CSV copy | None, or km only |
| Negative split | 0 to 10%, total time kept | Even pace only |
| Race predictions | Six distances from one result | Separate calculator |
| Time input | 25:00, 1:45:30 or 1h20m | Three separate boxes |
| Shareable | Link keeps your inputs | Resets on reload |
Tips
- Use the official race distance. A GPS watch often reads a little long on race day because you can't run perfect tangents.
- Add 5 to 10 seconds per km to your goal pace for hilly or hot races.
- Keep easy runs well slower than race pace. Many training plans put them over a minute per km slower than 5K pace.
- Running to lose weight? Pair your plan with the calorie deficit calculator so training and food line up.
- To add up the total time of several runs, use the time calculator.
Questions
How do I calculate my pace per km?
Divide your time in minutes by the distance in km, then turn the decimal into seconds. 28 minutes for 5 km is 5.6 minutes, which is 5:36 per km.
What pace is a 4-hour marathon?
About 5:41 per km or 9:09 per mile. Held evenly for all 42.195 km, 5:41 per km finishes in about 3:59:50.
How do I convert pace per km to pace per mile?
Multiply the pace per km by 1.609344. 5:00 per km is 300 seconds × 1.609344 = 483 seconds, which is 8:03 per mile. The calculator shows both at once.
What is a good 5K time?
It depends on age and experience. Many new runners take more than 30 minutes, and under 25 minutes is quick for a casual runner. Track your own progress rather than others.
How accurate are race time predictions?
They are reasonable between nearby distances, such as 5K to 10K. They get less reliable the further you predict, and assume you have trained for the longer distance.
What is the difference between pace and speed?
Pace is time per distance (5:00 per km). Speed is distance per time (12 km/h). Runners use pace; treadmills and cyclists usually use speed.
How long is a half marathon in km and miles?
21.0975 km, or 13.1094 miles. A full marathon is 42.195 km, or 26.2188 miles.
Can I use this for walking or cycling?
Yes. The maths is the same for any activity. The race predictor is tuned for running, so ignore it for cycling.