Pace Calculator
Enter any two of distance, time, and pace, and the rest is calculated automatically.
Predicted times from 5K to the full marathon, plus splits and calories, all at once.
Reference: 5K · 10K · 21.0975 (half) · 42.195 (full)
Enter it to also calculate calories
Average Pace
—
m's" / km
Average Speed
—
km/h
Finish Time
—
Total Distance
—
Mile Pace
—
Calories Burned
—
Intensity
—
RecoveryLSDTempoRaceAll-out
This pace at other distances? Prediction based on Riegel's formula
1km
—
1 km
3km
—
3 km
5K
—
5 km
10K
—
10 km
15K
—
15 km
Half
—
21.1 km
30K
—
30 km
Full
—
42.2 km
Per-km Splits
| Segment | Segment Time | Cumulative Time |
|---|---|---|
| Please fill in the inputs | ||
How is it calculated?
Pace calculation — it's simple division.
Pace (s/km) = Total time (s) ÷ Distance (km)Speed (km/h) = Distance (km) ÷ Time (hr) = 3600 ÷ Pace (s/km)
Predicting other distances — Riegel's formula (1981)
T₂ = T₁ × (D₂ / D₁)^1.06- Predicts your time over a different distance at the same effort. 1.06 is the endurance coefficient — how much pace slows as distance grows.
- Predicting a full marathon from a short distance (5K) is a bit optimistic. In practice, add 5–10% to be safe.
Calories — ACSM (American College of Sports Medicine) running formula
- Rough MET estimate:
MET ≈ Speed (km/h)(within the 6–18 km/h range) kcal = MET × Weight (kg) × Time (hr)- For the exact ACSM formula, see the calorie calculator — Go →
Source: Riegel P. (1981) Athletic Records and Human Endurance · ACSM Guidelines (American College of Sports Medicine)
Holding a pace on your own is genuinely hard
Instead of checking your watch every minute wondering "am I too fast? too slow?", it's much easier to form a crew with runners at your pace and run together. Find people to run with on the RunnerOn app.
