Race time predictor

Calculate race time predictor using the values and assumptions you provide.

Your inputs stay in your browser. Displayed results are rounded to a maximum of 12 significant digits.

Method and assumptions

Method version 1.0.0 · Updated October 18, 2026

Calculate

Formula: T₂ = T₁ × (D₂ / D₁)^1.06

Calculate race time predictor using the values and assumptions you provide.

knownTime: Recorded time (seconds)
knownDistance: Recorded distance (km)
targetDistance: Target distance (km)

Results depend on the assumptions entered; verify professional or safety-critical decisions independently.

Calculate with code

These short examples use the same inputs and core calculation as this tool. Adapt validation and formatting to your application.

JavaScript

const timeSeconds = 25 * 60, distanceKm = 5, targetKm = 10;
console.log(timeSeconds * (targetKm / distanceKm) ** 1.06 / 60); // Riegel estimate, minutes

TypeScript

const timeSeconds = 25 * 60, distanceKm = 5, targetKm = 10;
const predictedMinutes: number = timeSeconds * (targetKm / distanceKm) ** 1.06 / 60;
console.log(predictedMinutes);

Python

time_s, distance, target = 25*60, 5, 10
print(time_s * (target/distance)**1.06 / 60)  # Riegel estimate, minutes

Java

double minutes = 25*60 * Math.pow(10.0/5, 1.06) / 60;
System.out.println(minutes); // Riegel estimate

double minutes = 25*60 * Math.Pow(10.0/5, 1.06) / 60;
Console.WriteLine(minutes); // Riegel estimate