Pace calculator
A distance and a target time give your pace per kilometre and per mile, plus the splits.
- Runs in your browser — nothing you enter is uploaded
- No sign-up, no quotas, free to use as often as you like
How it works
Race planning comes down to one question: what pace do I need to hold? Once you have that, the splits tell you whether you are on it at any point in the race, which is the part that stops people going out too fast.
Pace and speed are different views of the same thing
Runners think in minutes per kilometre or mile, treadmills and cyclists think in kilometres or miles per hour. Both are shown, because you will need to convert between them the moment you step on a treadmill.
The splits are the useful part
Your time at 5 km, 10 km and halfway are what you check against on the day. Almost every bad race comes from running the first few kilometres faster than target and paying for it later — having the number in your head beforehand is the cheapest fix there is.
Standard distances
5 km, 10 km, half marathon at 21.0975 km and marathon at 42.195 km, all at their exact official lengths rather than rounded. A custom distance is there for everything else.
What it does not model
Hills, wind, heat and fatigue. A flat even-paced plan is the baseline; real races need adjustment, and most people slow down over the second half of a marathon no matter how well they planned.
Pace calculator — questions
What is a good 5K pace?
It varies enormously with age, training and terrain, so the honest answer is that your own previous times are the only meaningful comparison.
Are the race distances exact?
Yes — a half marathon is 21.0975 km and a marathon 42.195 km, not rounded.
Can I work out a pace for a distance not listed?
Yes. Choose custom and enter the distance in kilometres.
Does it account for hills?
No. It assumes even pacing on flat ground.
Does it convert to miles?
Yes. Pace per mile and speed in mph are always shown alongside the metric figures.