Enter a known race result and predict your finish time for other distances using the Riegel formula — the gold standard for race time prediction used by coaches worldwide.
Known race result
↓ View results below
Predicted Race Times
Based on the Riegel formula: T₂ = T₁ × (D₂/D₁)^1.06. Predictions assume equal fitness and conditions. Longer races may be slightly slower due to fatigue and pacing strategy.