Our predictions are based on statistical analysis of over 1.3 million finish times from real trail runners. While individual results vary based on conditions, training, and race-day factors, our predictions provide a reliable estimate for planning your race strategy and setting realistic goals.

The UTMB Index is a performance score that measures your trail running ability on a scale, typically ranging from 200 to 900+. It's calculated based on your finish times in UTMB-certified races, accounting for distance, elevation, and race difficulty. A higher index indicates faster performance.

You can find your UTMB Index by creating a free account on the official UTMB website (utmb.world). Your index is automatically calculated after completing UTMB-certified races. If you haven't run any certified races yet, you can estimate your index based on similar performances.

Yes! While our data comes from UTMB-certified races, the predictions work for any trail race. Simply enter the race distance and elevation gain, and we'll estimate your finish time based on runners with similar fitness levels tackling comparable courses.

Riegel's formula was designed for flat road races and doesn't account for elevation, terrain difficulty, or the unique challenges of trail running. Instead, we use actual finish times from 1.3M+ trail runners to predict your time. This means our predictions reflect real-world trail conditions—including how elevation gain affects pace—rather than theoretical calculations that can be wildly inaccurate for mountain races.