Health & Fitness Calculators

Race Time Predictor

Enter a known race distance and time to predict your equivalent time at a different target distance.

52:07
predicted time at 10km

Uses Riegel's formula: T2 = T1 × (D2/D1)^1.06 — a well-established endurance prediction model, though it works best for distances reasonably close to your known time and assumes comparable training/pacing for both distances.

How to use this tool

  1. 1Enter a distance and time you've actually raced or run hard.
  2. 2Enter your target race distance.
  3. 3See the predicted time.

Frequently asked questions

How accurate is this prediction?+

It works best for target distances reasonably close to your known one — predicting a marathon time from a 5K, for example, is much less reliable than predicting a 10K from a 5K.

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