basic

Marathon Time Predictor

Project a marathon finish time from a recent race.

Project your marathon finish time from a recent shorter-race time using the classic Riegel race-time formula.

Priya Venkatesan By Priya Venkatesan
Published Last reviewed 1 min read

Inputs

min
km

Results

Enter values and click Calculate to see results.
Was this helpful?

How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

T₂ = T₁ · (D₂ / D₁)1.06 (Riegel, 1981).

In depth

Project your marathon finish time from a recent shorter-race time using the classic Riegel race-time formula.