Race Time Predictor

Recent finish time

Scenarios are comparisons, not measurements of your endurance.

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Marathon equivalence also depends on distance-specific preparation.

Use this result for training paces →

Method and limitations

Riegel: T₂ = T₁ × (D₂ / D₁)k. Calculations use seconds, rounded only for display. Default k=1.06; 1.08 and 1.10 are alternative scenarios, not confidence intervals. A larger exponent gives slower times when projecting longer distances and faster times when projecting shorter distances.

No weather, elevation, training-volume or fueling adjustment is included. Riegel can be optimistic for recreational marathon runners. Read the research and limitations.