Running Pace Calculator

Turn any distance and finish time into pace per mile and km. Predict other race times with the Riegel formula and view practical training zones.

Pace from time + distance

Distance (km)Unit

HoursMinutesSeconds

Pace per mile

8:03/mi

7.5 mph average

Pace per km

5:00/km

12 km/h average

Distance (miles): 3.11 mi
Distance (km): 5 km
Total time: 25:00
Seconds per mile: 483
Seconds per km: 300

Race time predictor (Riegel formula)

T2 = T1 × (D2/D1)¹·⁰⁶ — a simple power-law model that works decently across common race distances.

Base distance (km)Base unit

Base hoursBase minutesBase seconds

Target distance (km)Target unit

Predicted time for target

0:52:07

Pace approx 8:23/mi / 5:13/km

Predictions are estimates. Longer distances usually slow average pace.

Training zones (pace per mile)

Threshold / recent race pace (min per mile, e.g. 7.5)

Zones are derived from this pace. Adjust to match your current fitness or a recent time-trial.

Easy / Recovery: 10:00/mi – 9:15/mi
Long runs: 10:30/mi – 9:30/mi
Tempo / Steady: 8:30/mi – 7:45/mi
Threshold / Marathon pace: 8:00/mi
Interval / VO2max: 7:30/mi – 6:45/mi
Repetitions / Speed: 7:00/mi – 6:00/mi

Pace and predictions

Pace is distance ÷ time. Race predictions use Riegel formula (exponent ~1.06). Training zones are rough % of max heart rate or pace ranges; individual response varies.

See heart rate zones and VO2 max.