π Running Pace Converter
min/km, min/mile, km/h, mph, plus finish-time predictions for every race distance.
All pace and speed units
Race Time Predictor
Predicted finish times at your pace (Riegel formula adjusted):
| Distance | Predicted Time |
|---|
How to Use This Pace Converter
Runners think in pace (minutes per kilometer or mile) while treadmills and bike computers show speed (km/h or mph). Enter your number in whichever unit you have, and this tool converts to all the others, then predicts your finish times from 5K to marathon.
Enter your pace or speed and pick its unit.
Read every equivalent unit in the results panel.
Check the race predictor table for 5K, 10K, half marathon, and marathon finish estimates.
Pace vs Speed
Pace is time per distance (5:30 min/km), speed is distance per time (10.9 km/h). They are reciprocals: faster pace means a smaller number, faster speed means a bigger number. Runners prefer pace because race strategy is planned per kilometer or per mile; a 5:00/km runner knows each kilometer should take five minutes.
The US runs in minutes per mile, most of the world in minutes per kilometer. One mile is 1.60934 km, so a 5:00/km pace equals about 8:03/mile. Treadmills usually display mph or km/h, which is why the conversion matters mid-workout.
The Math
The race predictor uses the Riegel formula, which accounts for the fact that pace slows as distance grows: T2 = T1 Γ (D2/D1)^1.06. A runner holding 5:00/km for 5K will not hold it for a marathon; the exponent models that fade from real race data.
Worked Example
You run 10K in 55 minutes, a 5:30/km pace. In min/mile: 5.5 Γ 1.60934 = 8.85 min/mile, or 8:51 per mile. As speed: 60 Γ· 5.5 = 10.9 km/h (6.8 mph). Predicted marathon: 5.5 min/km Γ 42.195 km with Riegel fade β 4 hours 18 minutes, a realistic target for that fitness level.
Training With Pace
Most training plans prescribe zones as percentages of race pace: easy runs at 65 to 75 percent of 5K effort, tempo at about 85 to 90 percent. Convert your goal race pace once with this tool, then derive every workout target from it. And remember that heat, hills, and altitude all slow pace; adjust expectations rather than forcing the numbers.
Frequently Asked Questions
How do I convert min/km to min/mile?
Multiply by 1.60934. A 5:00/km pace equals 8:03 per mile. This works because a mile is 1.60934 kilometers long.
What is a good 5K pace for a beginner?
Around 6:30 to 7:30 per km (10:30 to 12:00 per mile), finishing in 32 to 37 minutes. Anything under 30 minutes (6:00/km) is a strong beginner result.
How do I convert pace to speed in km/h?
Divide 60 by the pace in min/km. A 5:00/km pace is 60/5 = 12 km/h. For mph, divide the km/h result by 1.60934.
Why does my treadmill show a different pace than my watch?
Treadmills measure belt speed (mph or km/h) while watches measure GPS pace. Calibration differences, incline settings, and GPS error all create small gaps. Trust the treadmill for indoor workouts.
How accurate are race time predictions?
Within a few percent for well-trained runners. The Riegel formula models fatigue from real race data, but heat, hills, and undertraining can push actual times slower than predicted.