Calorie Burn Calculator

Calculate calories burned during exercise based on weight, duration, activity type (MET), and heart rate. Track your workout intensity.

The headline figure is a three-way product: the activity's MET value times your weight in kilograms times duration in hours. A MET is a multiple of resting energy use, so cycling at 6 METs for half an hour at 70 kg gives 210 kcal. Because all three terms multiply, none of them dominates — nudge the MET value, your weight or the clock by ten percent and each produces the identical 21-calorie shift, and doubling any one of them doubles the answer. That symmetry is the most useful thing to understand here: an extra fifteen minutes and a slightly harder pace are interchangeable levers. A second, quite different estimator sits underneath. If you supply both a heart rate and an age, the tool computes an alternative from heart rate intensity — your age-derived maximum sets the denominator, intensity scales a per-minute rate against body weight, and the total fills the HR Calories row, which reads 63.8 kcal for 70 kg over 30 minutes at 140 bpm and age 30. That path only takes over the headline number when the MET field is cleared to zero; while any MET value is present the MET result wins and heart rate merely populates its own row for comparison. The two disagree substantially by design, since the heart-rate model is a coarse linear approximation. The Intensity Level label is read straight off the MET value, switching to Moderate at 3 and Vigorous at 6. Not modelled: fitness level, terrain, gradient, altitude, heat, mechanical efficiency, or the resting calories you would have burned anyway during the same half hour.