🏃 Running & Race Split Calculator
Running Pace Calculator
Calculate running pace, target finish times, split charts, and Riegel race predictions.
h
m
s
8:00 / mi
(4:58 / km)
Standard Races:
5K (25:00)
10K (50:00)
Half Marathon (1:45:00)
Marathon (3:45:00)
1 Mile (7:00)
Pace per Mile
8:00 min/mi
Pace per Kilometer
4:58 min/km
Speed (MPH)
7.49 mph
Speed (km/h)
12.06 km/h
Riegel Race Time Predictions (Based on Current Pace):
| Event | Distance | Predicted Time | Average Pace |
|---|
The Mathematics of Running Pace & The Riegel Formula
Pace is defined as elapsed time divided by distance traveled: $\text{Pace} = \frac{\text{Time}}{\text{Distance}}$.
To forecast marathon and half-marathon race times from shorter benchmark distances, coaches and exercise physiologists use Peter Riegel's endurance formula (1977):
T₂ = T₁ × ( D₂ / D₁ )^1.06
The fatigue factor exponent $1.06$ accurately models the physiological drop in average velocity that occurs over longer continuous aerobic efforts.