Free Trail Running Calculators

Predict your trail race finish time using ITRA km-effort, ultra fatigue modeling, and terrain multipliers.

Find your grade-adjusted pace for any slope. Two modes: discover your flat effort equivalent, or target a pace at a given gradient.

Convert running pace between min/km, min/mi, km/h, and mph. Includes a splits table with trail distances up to 100km.

Convert trail gradients between %, degrees, ratio, and rise/run. See the Minetti energy cost and power hike threshold.

Estimate the performance index range (0-1000) a trail race result produces - ITRA score and UTMB Index style - from distance, elevation gain, and finish time.

Calculate your ITRA km-effort and unofficial performance score for any race result. See your indicative UTMB stone tier.

Get hourly calorie, carbohydrate, fluid, and sodium targets for your trail race. Adjusts for intensity, heat, and altitude.

Build a custom sports drink from bulk ingredients. See glucose:fructose ratio, osmolality, and concentration in real time. Load brand presets to understand what commercial products contain.

Upload a GPX file to see your route on an interactive map, explore the elevation profile, gradient heatmap, and waypoints. Get full race stats including km-effort score.

Enter your race checkpoints and goal time to get estimated arrival times at every aid station, segment paces, and hiking zones.

Estimate how temperature, altitude, and night running can inflate your trail race time - broken down factor by factor for UTMB, CCC, Lavaredo, Hardrock, and Western States.