Pace CalculatorFree online fitness & health calculator — instant results, no sign-up
Running pace, speed and finish time.
For general information only. This is not medical advice, diagnosis, dosing guidance or a treatment recommendation. Talk to a doctor or other qualified health professional about your health, pregnancy, or diet.
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How the result changes with distance
Each row below was calculated with this tool, keeping every other input at its default and changing only distance from half to one and a half times the default value. Use it to see how sensitive the answer is before you enter your own numbers.
| Distance (km) | Pace per km | Pace per mile | Speed |
|---|---|---|---|
| 5 | 10:00 | 16:06 | 6 km/h |
| 7.5 | 6:40 | 10:44 | 9 km/h |
| 10 (default) | 5:00 | 8:03 | 12 km/h |
| 13 | 3:51 | 6:11 | 15.6 km/h |
| 15 | 3:20 | 5:22 | 18 km/h |
About the Pace Calculator
This calculator determines running pace, average speed, and estimated marathon finish time from a given distance and duration. Runners, walkers, and cyclists use it to evaluate training splits, pace consistency, and target race goals.
- Distance
- The total distance traveled in kilometers (km), typically between 0.1 and 100.
- Time
- The total elapsed duration in minutes, typically between 1 and 1,000.
Formula and method
s = (Time in minutes × 60) / Distance in km Pace per km = format_time(s) Pace per mile = format_time(s × 1.609344) Speed (km/h) = Distance in km / (Time in minutes / 60) Marathon finish (hours) = (s × 42.195) / 3600
- sPace expressed in seconds per kilometer
- 1.609344Conversion factor representing kilometers per statute mile
- 42.195Standard official marathon distance in kilometers
The calculator converts total minutes into seconds and divides by kilometers to find seconds per kilometer, formatting it as minutes and seconds (mm:ss). It multiplies this by 1.609344 to obtain pace per mile, divides kilometers by hours to yield speed rounded to two decimal places, and projects marathon duration across standard 42.195 km.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Distance10 km
- Time50 minutes
Results
- Pace per km5:00
- Pace per mile8:03
- Speed12 km/h
- Marathon at this pace3.52 hours
How to use the Pace Calculator
- 1Convert elapsed minutes to seconds by multiplying by 60.
- 2Divide total seconds by kilometers to determine seconds per kilometer.
- 3Convert seconds per km into mm:ss format for kilometer pace, and scale by 1.609344 for mile pace.
- 4Calculate speed by dividing kilometers by elapsed hours, and project marathon finish time by multiplying per-kilometer pace by 42.195 km.
Reading your result
Pace values show the exact time required to cover one kilometer or one mile at an even effort level. Speed indicates average velocity in kilometers per hour. The marathon projection provides an ideal finish time in decimal hours assuming that current pace is sustained without fatigue across 42.195 km.
Limitations
The calculation assumes an entirely constant pace over flat terrain without stopping. It does not account for elevation gain, weather, terrain friction, or physiological fatigue over longer distances.
Common questions
How does the tool convert pace from kilometers to miles?+
It multiplies the seconds per kilometer by 1.609344, which is the exact number of kilometers in an international statute mile, and formats the result into minutes and seconds.
Why is the marathon finish shown in decimal hours?+
The algorithm divides the total projected seconds for 42.195 kilometers by 3,600 and rounds to two decimal places, giving a simple fractional hour representation such as 3.52 hours.
Can this be used for treadmill running?+
Yes. If your treadmill reports distance in kilometers and time in minutes, entering those values provides your pace splits and average kilometers per hour.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
Further reading
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Results are estimates for informational purposes and are not financial, medical or legal advice.