Predict your race finish time for 5K, 10K, half marathon, or marathon based on your pace or a previous race time. Convert between distances.
Enter your values below
Select your target race distance.
Enter your pace in min:sec format (e.g., 8:30).
Optional: enter a previous race for prediction.
Your finish time for the known distance.
How this calculator works
Uses Riegel's formula to predict race times across distances, with an endurance exponent of 1.06 to account for fatigue over longer distances.
Common questions about this calculator
These calculators are for informational purposes only. While we strive for accuracy, results should not be used as the sole basis for important decisions.
