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Pace Calculator

Work out your running pace per kilometre or mile, your finish time for a race, or how far you ran. Includes speed and race time predictions.

Calculated on your device
Enter a number, for example 1250 or 19.99.
Enter a number, for example 1250 or 19.99.
Enter a number, for example 1250 or 19.99.
Enter a number, for example 1250 or 19.99.
Enter a number, for example 1250 or 19.99.
Enter a number, for example 1250 or 19.99.
Embed this calculator on your website

Free to use on your blog or business site. Copy this code and paste it into your page's HTML.

Works in WordPress (Custom HTML block), Wix (Embed code), Squarespace (Code block), Webflow and Shopify pages.

How to use the pace calculator

  • Find my pace: enter the distance and your time to get your pace per kilometre and per mile, and your speed.
  • Find my finish time: enter a distance and the pace you plan to run.
  • Find the distance: enter how long you ran and your pace.

Use the race buttons to fill in 5K, 10K, half marathon (21.0975 km) or marathon (42.195 km).

Pace formulas

Pace = Time ÷ Distance
Time = Pace × Distance
Speed (km/h) = 60 ÷ pace in minutes per km
1 mile = 1.609344 km

Worked example

A 10K in 50:00: 50 minutes ÷ 10 km = 5:00 per km, which is 8:03 per mile and 12 km/h (7.46 mph).

At the same 5:00 per km, a marathon would take 3:30:59. The Riegel formula, which allows for slowing over longer distances, estimates about 3:50:01.

Predicting race times

Keeping exactly the same pace over a longer race is hard, so the calculator also shows the Riegel formula, a widely used estimate published by Peter Riegel in 1981: T₂ = T₁ × (D₂ ÷ D₁)1.06. It works best for races between about 3.5 minutes and 4 hours, and for runners who have trained for the distance.

Want to know how many calories you burn in a day? Try the calorie calculator.

Frequently asked questions

How do I convert pace per km to pace per mile?

Multiply the pace by 1.609344. 5:00 per km is 8:02.8 per mile, which rounds to 8:03.

How long is a half marathon?

21.0975 km, or 13.1094 miles. A marathon is 42.195 km (26.2188 miles).

Formulas checked 29 October 2026. How we test our calculators. This calculator gives general estimates for adults and is not medical advice. Talk to a doctor or dietitian about your own health.