CALCULATOR 13

Pace Calculator

Find your pace, finish time or distance from the other two, and predict your race times.

Pace

Enter a distance.

For general information only; not medical advice. Consult a qualified professional before making health decisions.

How this is calculated

Pace = time ÷ distance
Time = pace × distance
Distance = time ÷ pace
Speed = 60 ÷ pace (min/km) km/h

Race predictions (Riegel)

T₂ = T₁ × (D₂ ÷ D₁)^1.06

Predictions assume equal training for each distance. They're most reliable from a recent race between about 1.5 km and the marathon, and less reliable the further you predict (for example, a 5K to a marathon).

Sources

Riegel PS (1981), Athletic records and human endurance. American Scientist 69:285–290.

Pace, time and distance

Any two give you the third. Planning a 10K at 6:00 per kilometre? That's a 1:00:00 finish. Ran 5 km in 27:30? That's 5:30 per kilometre, or about 10.9 km/h. Switch units to work in miles.

How race predictions work

In 1981 Pete Riegel showed that race times across distances follow a simple power law: double the distance and your time a little more than doubles, because pace slows as distance grows. The exponent of 1.06 fits well-trained runners. If you haven't trained for the longer distance, expect to run slower than predicted—especially for the marathon.

Using pace in training

Most easy running should feel conversational—often 60 to 90 seconds per kilometre slower than your 5K race pace. Pair pace with the heart rate zone calculator to keep easy days easy.

Frequently asked questions

How do I calculate my running pace?

Divide your time by the distance. 25 minutes for 5 km is 5 minutes per kilometre.

What is a good 5K time?

For recreational runners, finishing a 5K in 25–35 minutes is common. Under 25 minutes (5:00 per km) is quick for most adults; beginners walking and running often finish in 35–45 minutes.

How accurate are race time predictions?

From a recent race they're usually within a few percent for nearby distances. Predicting a marathon from a 5K is the least reliable, because endurance training matters much more over 42 km.

How do I convert pace from km to miles?

Multiply pace per kilometre by 1.609. A 5:00 per km pace is about 8:03 per mile. The calculator shows both.