Running Pace Calculator

How running pace is calculated

Pace is simply time divided by distance:

Pace per mile = total time ÷ distance in miles
Pace per kilometer = total time ÷ distance in kilometers (1 mile = 1.609344 km)

The predicted finish times multiply your pace by the standard race distances — 5K = 5 km, 10K = 10 km, half marathon = 21.0975 km, marathon = 42.195 km. They answer the question "what would I run if I held exactly this pace the whole way?"

Read predictions with care: almost nobody holds their 5K pace for a marathon. Shorter races are run at a faster relative effort, and fatigue, hills, heat, and fueling all slow longer efforts. Treat the predictions as a clean same-pace comparison — and as a starting point for a training plan — rather than a promise. A common real-world pattern is that your sustainable pace gets roughly 15–30 seconds per mile slower each time the distance doubles.

Pace vs. speed: runners talk in pace (minutes per mile) because it's easy to check against mile markers and race clocks. Speed (mph or km/h) is the same effort expressed the other way — it's what a treadmill usually displays, so the speed line helps you set the belt to match your outdoor pace.