Running Pace Calculator

Pace from a run, finish time from a pace, or race predictions from a recent result.

How to use the pace calculator

  1. Pace from a run: pick a distance and enter your finish time. You get pace per km, pace per mile, and speed in km/h and mph.
  2. Finish time from pace: enter a target pace (per km or per mile) and a distance to predict your finish time.
  3. Race-time predictor: enter a recent race result and the Riegel formula forecasts your 5K, 10K, half-marathon, and marathon times.
  4. Custom distances are available in every mode — type any distance in km or miles.

Frequently asked questions

How is running pace calculated?

Divide your finish time by the distance. A 50-minute 10K is 50 ÷ 10 = 5:00 per kilometer. Multiply that pace by 1.609344 to get minutes per mile (5:00/km ≈ 8:03/mi).

What is the Riegel formula?

The Riegel formula predicts race times from a recent result: new time = old time × (new distance ÷ old distance)^1.06. It was developed by researcher Peter Riegel in 1977 and works best when the two races are close in distance.

What is a good running pace for a beginner?

Most new runners settle around 6:30–8:00 per kilometer (10:30–13:00 per mile) for easy runs. Pace is personal — consistency beats speed when you are starting out.

How do I convert min/km to min/mi?

Multiply by 1.609344. A 5:00/km pace equals about 8:03/mi. This calculator shows both automatically.

Are race predictions accurate?

Riegel predictions are estimates, not guarantees — they assume similar fitness, course, and conditions. Predictions between nearby distances (5K to 10K) tend to be closer than big jumps (5K to marathon).

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Questions or feedback?

Spotted a wrong number or want a feature? Email [email protected] — every report is read by the indie dev behind the codex.