How a Prediction is Made

Racr gives you a realistic estimate of your finish time by combining your unique fitness profile with the specific challenges of your race course. Here is a look under the hood.

1. Your "Fitness Signature"

We don't just look at your average pace. We scan your last 12 months of running interactions on Strava to calculate your Grade Adjusted Pace (GAP).

What is GAP?

Running uphill is harder than running on flat ground. GAP normalizes your pace to show how fast you would be running if every run was flat. This reveals your true fitness engine, regardless of terrain.

2. The Course Profile

Every race is different. A 50k in the Alps is not the same as a flat city marathon.

Distance: The total length of the course.
Elevation Gain: The total amount of climbing.

We analyze the .gpx file or your manual inputs to understand exactly how tough the course is.

3. The Prediction Formula

We predict your time by taking your historical GAP and slowing it down based on the course's specific elevation gain.

Roughly speaking, we add significant time penalties for every 100 meters of climbing, simulating the fatigue and reduced speed of uphill running. This creates a finish time that respects both your speed and gravity.