Free running calculators

Convert min/km, min/mile, and km/h instantly. Includes finish time predictions.

Predict your marathon or half from any known race result using the Riegel formula.

Calculate your 5 HR training zones with Karvonen or % of max HR method.

Estimate your VO2 max and VDOT score. See equivalent times across all distances.

Check your BQ time by age group and gender. Includes cutoff buffer analysis.

Generate per-km splits for even, negative, or positive split strategies.

MET-based calorie estimate by distance, pace, and body weight.