Calories Burned (MET) Calculator

MET stands for Metabolic Equivalent of Task. One MET is the energy expended at rest (approximately 3.5 mL O2/kg/min, or roughly 1 kcal/kg/hour). Activities are assigned MET values relative to resting. Walking at a moderate pace is about 3.5 METs; running at 8 min/mile is about 11.5 METs. MET values for hundreds of activities are published in the Compendium of Physical Activities by the ACSM.

The formula Calories = MET x 3.5 x weight(kg) / 200 x minutes converts MET values to kilocalories. The 3.5 factor converts MET to mL O2/kg/min (since 1 MET = 3.5 mL/kg/min). Dividing by 200 converts to kcal/kg/min (since 1 L of O2 consumed = approximately 5 kcal, and 1000/5 = 200). Multiplying by weight and duration gives total kcal.

MET-based estimates are population averages and have individual error of approximately 10 to 20 percent. Actual calorie burn varies with fitness level, body composition, terrain, and environmental conditions. Wearable devices also use METs as a basis but add heart rate correction. The formula provides a useful estimate for planning and tracking purposes.

The Compendium of Physical Activities (compiled by Barbara Ainsworth and colleagues, supported by the ACSM) is the authoritative reference for MET values. It includes over 800 activities. A freely accessible version is available through Arizona State University at sites.google.com/site/compendiumofphysicalactivities.

Yes. Calorie burn is directly proportional to body weight in the MET formula. A 100 kg person burns twice as many calories as a 50 kg person performing the same activity at the same MET for the same duration. This is because more mass requires more energy to move. Fitness level also affects efficiency, but weight is the primary variable in this formula.