Running
Pace.Calculator
Enter any two of pace, time, and distance — get the third instantly. Switch between miles and kilometers. No sign-up, works offline.
Calculate
Race splits
Cumulative time you should hit at each mile to reach your goal.
Equivalent race times
Ran one race? Predict your times at other distances (Riegel formula — an estimate, not a guarantee).
How to use this running pace calculator
Your running pace is simply how long it takes you to cover a set distance — usually written as minutes and seconds per mile or per kilometer. This calculator links the three numbers every runner cares about: pace, time, and distance. Pick what you want to work out at the top, enter the other two, and the answer updates as you type.
- Pace — enter a distance and a finish time to see your pace per mile or per kilometer, plus your equivalent speed in mph or km/h.
- Time — enter a distance and a goal pace to see the finish time you are on track for.
- Distance — enter a time and a pace to see how far that takes you.
Use the Miles / Kilometers toggle to switch units at any time — the calculator converts your distance and pace automatically. The race presets (mile, 5K, 10K, half marathon, marathon) fill in the exact distance so you don't have to remember that a marathon is 42.195 km.
Splits and pacing strategy
Hitting a goal time is much easier when you know the splits you need to run — the cumulative time you should see on the clock at each mile or kilometer. The Race splits section builds that table for any goal, and lets you choose even splits, a negative split (starting a little slower and finishing faster, a strategy many runners use to avoid fading), or a positive split. Seeing the splits in advance turns a vague target like "sub-4 marathon" into concrete checkpoints: roughly 9:09 per mile, every mile, for 26.2 miles.
Predicting your times at other distances
If you've raced recently, the Equivalent race times predictor estimates what you could run at other distances using the Riegel formula. It's a useful reality check when you set a goal: a 22-minute 5K, for example, suggests roughly a 45-minute 10K and a 1:40 half marathon. The further the predicted distance is from the one you actually ran, the rougher the estimate — endurance, training, and race-day fueling all matter — so treat the numbers as a starting point rather than a promise.
Training, treadmills, and race-specific pages
For day-to-day running, your easy, tempo, threshold, and interval paces are all slower or faster than race pace; the training paces page estimates them from a recent 5K. If you run indoors, the treadmill pace calculator converts your goal pace into belt speed in mph and km/h. And if you're training for a specific race, the 5K, 10K, half marathon, and marathon pages show the pace and finish times for that distance at a glance. Everything runs in your browser — no account, no app, and it keeps working offline.
Frequently asked questions
How is running pace calculated?
Pace is your time divided by your distance. For example, running 5 km in 25 minutes is 1,500 seconds ÷ 5 km = 300 seconds per km, or 5:00 per kilometer (about 8:03 per mile). This calculator does the arithmetic for you and also works in reverse — give it a pace and distance to get a finish time, or a pace and time to get a distance.
What is a good running pace?
It depends entirely on your fitness, the distance, and the terrain — there is no universal "good" pace. Many recreational runners cover a mile somewhere between 8 and 12 minutes. Rather than chase someone else's number, use the equivalent-times predictor to set realistic goals from a race you have actually run.
How do I convert pace between minutes per mile and minutes per kilometer?
A kilometer is shorter than a mile (1 mile ≈ 1.609 km), so your per-kilometer pace is faster (a smaller number) than your per-mile pace. To convert per-mile pace to per-kilometer, multiply by 0.621. Toggle the Miles/Kilometers switch and the calculator converts everything for you.
What is a negative split?
A negative split means running the second half of a race faster than the first. It is a common pacing strategy because starting conservatively helps you avoid blowing up late. Switch the split strategy in the Race splits section to see even, negative, or positive split times for your goal.
How accurate is the race-time predictor?
It uses the Riegel formula, T₂ = T₁ × (D₂ ÷ D₁)^1.06, a well-known endurance model. It is a reasonable estimate when the two distances are not wildly different, but it tends to be optimistic for much longer races (predicting a marathon from a 5K, for instance) because it does not account for endurance training or fueling. Treat it as a guide, not a guarantee.
Does this pace calculator work on a treadmill?
Yes. Calculate the pace you want, then use the Treadmill pace calculator to convert it to belt speed in mph or km/h. US treadmills usually display mph; most others use km/h.
Is it free, and does it work offline?
Yes to both. There is no sign-up, and all calculations run in your browser, so once the page has loaded it keeps working without a connection.