About TrailMath

Why we built it

Trail running is full of numbers that road-running tools get wrong: grade-adjusted pace, vertical gain, aid-station logistics, fueling over many hours. We wanted tools that treat the mountain as the main variable, not an afterthought.

Every calculator on the site is free, runs in your browser, and is documented with the assumptions and research behind it so you can judge whether it fits your race.

How we source race data

Headline figures for each race - distance, elevation gain and loss, cutoff times, and the highest point - are checked against the organiser's official course page. Each race page records the exact source URL and the date it was last verified.

Per-checkpoint splits are approximate because courses shift slightly between editions; we say so on every page rather than implying false precision. We re-verify the headline figures before each season.

The science behind the tools

Our grade-adjusted pace and effort models draw on the energy-cost-of-running literature (for example Minetti's work on the metabolic cost of gradient) and established pacing research. Where a tool makes a simplifying assumption, the tool page explains it.

We would rather show our reasoning and let you adjust inputs than present a single black-box number.

Privacy and independence

TrailMath is hosted in Europe. We do not sell your data and we do not run third-party advertising trackers. The calculators do not require an account.