🏃Running Pace Calculator
Enter any two of pace, time, and distance — the third is calculated instantly. Get a full split table and predicted finish times for 5K, 10K, half marathon, and marathon.
This tool provides general information and is not medical advice. Exercise intensity should match your own fitness and health. Please consult a physician before starting a new exercise routine or training at high intensity—especially if you have any heart condition, injury, or health concern.
Free Running Pace Calculator Online
Chasing a target time? Our free Running Pace Calculator works out the numbers the moment you enter them. As a fast and reliable running pace calculator, it solves whichever value you need — pace, time, or distance — from the other two, so you can plan a run, hit a goal time, or check how fast a session really was.
But it does more than one figure. See a full split table showing your cumulative time at every kilometre or mile, get predicted finish times for the 5K, 10K, half marathon, and marathon from your pace, and switch freely between metric and imperial. Whether you're training for a race, pacing a long run, or just curious how your splits add up, everything's laid out clearly so you can plan with confidence.
Simply enter any two values to see the rest instantly. No sign-up, no downloads, no limits — just clear numbers whenever you need them. Learn more at the FAQ or About pages.
About the Running Pace Calculator
Key features
Solve any of the three values
Enter pace + distance to get time, time + distance to get pace, or pace + time to get distance. Leave whichever field you want computed blank and the tool fills it instantly.
Per-km / per-mile split table
When pace and distance are both known, a full split table appears showing the cumulative time at every kilometre or mile. Partial final splits (e.g. the 0.195 km at the end of a marathon) are included with their own time.
Race finish-time predictions
From any known pace, the tool instantly estimates your finish time for the 5K (5 km), 10K (10 km), half marathon (21.0975 km), and marathon (42.195 km). Useful for choosing a target pace before race day.
Metric and imperial
A unit toggle switches between km (min/km pace, distances in km) and mi (min/mi pace, distances in miles). Pace and distance values in the input fields convert automatically when you switch.
Distance presets
One-tap buttons for 5K, 10K, Half, and Marathon fill the distance field instantly. The preset labels stay the same in both unit modes; the underlying distance converts to km or miles as needed.
Fully private, no sign-up
Calculations run entirely in your browser. No data is stored, logged, or sent to any server. No account is required and there are no usage limits.
How the calculations work
Core formula
Total time (seconds) = pace (seconds per unit) × distance (units). All three values are linked by this identity: knowing any two gives the third directly.
Pace from time + distance
Pace (s/unit) = total time (s) ÷ distance. For example: 3000 s ÷ 10 km = 300 s/km = 5:00 min/km.
Time from pace + distance
Total time (s) = pace (s/unit) × distance. For example: 300 s/km × 42.195 km = 12658.5 s = 3:30:58.
Distance from pace + time
Distance = total time (s) ÷ pace (s/unit). For example: 3600 s ÷ 300 s/km = 12 km in one hour at 5:00 min/km.
Unit conversion
1 mile = 1.60934 km. Pace conversion: min/mi = min/km × 1.60934. Distance conversion: miles = km × 0.621371. All conversions are exact to 5+ significant figures.
Race predictions
Predicted time = pace (converted to s/km) × race distance (km). The pace is converted to per-km internally regardless of the selected unit, so all four standard race distances are accurate in both modes.
Pace vs speed
Pace and speed measure the same thing from opposite directions. Pace is time per distance — for example, 5:00 min/km tells you each kilometre takes five minutes. Speed is distance per time — for example, 12 km/h tells you how far you travel in one hour. Runners almost universally use pace because it translates directly to race planning: if your pace is 5:00 min/km and the race is 10 km, you know immediately that 50:00 is your target. Speed requires an extra step to reach the same conclusion.
To convert: speed (km/h) = 60 ÷ pace (min/km). At 5:00 min/km that is 60 ÷ 5 = 12 km/h. In miles: speed (mph) = 60 ÷ pace (min/mi).
A note on predictions and safety
Race finish-time predictions assume perfectly even pacing with no elevation change, fatigue, or environmental variation. Real race performance differs from even-pace projections. Use predictions as a starting reference and refine them with your own training data and race experience.
Frequently Asked Questions
How does the pace calculator work?
Enter any two of pace, time, and distance and the tool instantly calculates the third — no button or page refresh needed. Leave pace blank to compute it from time and distance. Leave time blank to compute it from pace and distance. Leave distance blank to compute it from pace and time. Once the result is shown, a per-kilometre or per-mile split table and race finish-time predictions also appear automatically.
Is it free?
Completely free. No sign-up, no downloads, no limits — calculate as many times as you like on any device.
What can it calculate?
It solves any one of the three core running values from the other two:
— Pace from time + distance: useful after a run to find out how fast you ran each km or mile.
— Total time from pace + distance: useful before a race to predict your finish time from a target pace.
— Distance from pace + time: useful to see how far you covered in a given time at a set pace.
Does it show splits?
Yes. When both pace and distance are known — either entered or computed — a full split table appears below the results. It shows your cumulative time at every kilometre or mile, so you can see exactly where you will be at each segment of your run. For distances with a partial final unit (such as 42.195 km), the last row shows the time for that partial segment and the total finish time.
Can it predict race finish times?
Yes. Once pace is known — either entered or computed — the tool estimates your finish time for the 5K (5 km), 10K (10 km), half marathon (21.0975 km), and marathon (42.195 km). These predictions assume you hold your entered pace evenly throughout the race.
Does it support metric and imperial?
Yes. Use the km / mi toggle at the top of the calculator to switch units at any time. Existing pace and distance values convert automatically — so if you switch from km to mi, your 5:00 min/km pace becomes 8:03 min/mi and a 10 km distance becomes 6.214 miles. The split table and race predictions update to reflect the new unit too.
What is the difference between pace and speed?
Pace is time per distance unit: for example, 5:00 per km means it takes five minutes to cover each kilometre. Speed is distance per time unit: for example, 12 km/h means you cover 12 km in one hour. The two are inverses of each other. Runners and coaches typically use pace because it makes race planning straightforward — if your pace is 5:00 min/km and you are running a 10 km race, you know immediately that your finish time will be 50:00.
Are the race finish time predictions guaranteed?
No. The predictions assume you maintain your entered pace evenly for the entire race. Real race performance varies with course elevation, weather, pacing strategy, fatigue, and nutrition. Use the predictions as planning estimates rather than fixed targets, and adjust based on your own training experience and race conditions.
Is my data stored anywhere?
No. All calculations happen entirely in your browser. Your inputs are never stored, sent to a server, or shared with any third party.
Does it work on mobile?
Yes. The calculator is fully responsive at all screen sizes. Inputs, the unit toggle, distance presets, the results panel, and the split table all work on phones and tablets without horizontal overflow. The split table scrolls horizontally if needed on very narrow screens.