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Running Pace Calculator

Enter any two of distance, time and pace to find the third, with pace per km, per mile, and speed.

Quick presets

Pace Calculator

Race:

Pace
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Race predictions Riegel formula
Splits even pace

Runs in your browser — nothing you enter is uploaded or stored.

ToolFeather · Splits + predictions
Scratchpad auto-saved
Stored in this browser (localStorage)

About the Pace Calculator

This is a three-way calculator for runners: give it any two of distance, time and pace, and it solves for the third. Pick your distance unit (kilometres or miles), enter the values you know, and press the button for the value you want to find — Find time, Find pace or Find distance.

Times use an hh:mm:ss format (you can drop the hours for shorter runs, e.g. 50:00), and pace is mm:ss per unit of distance (e.g. 5:00 per km). Whatever you calculate, the results panel always shows the full picture: total time, pace per kilometre and per mile, distance, and speed in both km/h and mph — so you never have to convert by hand.

Use it to set a target race pace, predict a finish time from your training pace, or work out how far a planned run will take. All calculations happen in your browser, instantly and privately.

Examples

10 km at 5:00/km → Find time → a 50:00 finish.
Ran 21.1 km in 1:45:00 → Find pace → about 4:59/km.
45 minutes at 6:00/km → Find distance → 7.5 km.

Frequently asked questions

5 answers
How do I enter a time or pace?
Times use hours:minutes:seconds, and you can omit hours for short runs (50:00). Pace is minutes:seconds per kilometre or mile, like 5:00.
Which two values do I need?
Any two of distance, time and pace. Enter those, then press the button for the one you want the tool to calculate.
Does it handle both km and miles?
Yes. Choose your distance unit, and the results always show pace per km and per mile plus speed in km/h and mph.
Can it predict my race finish time?
It can, if you assume an even pace. Enter the race distance and your target pace, then Find time. Real races vary with terrain and fatigue.
Is my data uploaded?
No. Every calculation runs in your browser and nothing you enter is stored or sent anywhere.