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Race Predictor
Predict your finish time at any distance based on a recent race, using the Riegel formula (T₂ = T₁ × (D₂/D₁)^1.06).
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Enter a time to see the result.
Riegel formula: Riegel PS, "Athletic Records and Human Endurance", American Scientist 69 (1981): 285-290. It assumes the same fitness and race conditions at both distances; results vary with pacing, terrain and temperature.