Calories Burned Calculator

MET, short for Metabolic Equivalent of Task, is a standardized way of expressing how energetically demanding an activity is relative to sitting quietly at rest — by definition, one MET represents the energy cost of sitting still, and an activity with a MET value of 8 (like jogging) burns roughly eight times as much energy per unit time as sitting quietly does. This relative-to-rest framing is genuinely useful because it creates a single comparable scale across an enormous range of activities, from the lowest-intensity daily tasks up through elite-level athletic effort, all expressed on the same consistent numeric scale.

The specific MET values used in exercise science and calculators like this one trace back to the Compendium of Physical Activities, an ongoing research project (first published in the early 1990s and periodically updated since) that has systematically measured and cataloged the energy cost of hundreds of distinct activities, from walking and cycling through gardening, housework, and countless recreational and occupational tasks. This compendium represents a substantial body of accumulated exercise physiology research, and it's exactly why MET-based calorie estimation is the standard approach used across fitness apps, research studies, and clinical exercise recommendations — it's grounded in real measured data rather than a simplified guess.

The formula itself — MET times body weight in kilograms times time in hours — reflects a genuinely important physiological principle: heavier bodies require more energy to perform the same physical task, since more mass has to be moved and supported, which is why this calculation scales directly with body weight rather than treating calorie burn as purely activity-dependent. Two people doing the identical workout at the identical intensity level will burn meaningfully different total calories if their body weights differ significantly, and MET-based calculation correctly captures this rather than assuming a uniform calorie burn regardless of who's doing the activity.

The method's real limitation is exactly the flip side of what makes it broadly useful: MET values represent population averages for a defined activity category, which necessarily glosses over real variation in individual fitness level, exact pace or intensity within that category, and personal metabolic differences. A MET value for 'running' represents some average pace and effort level across the population that value was measured from — an individual runner's actual calorie burn at their specific pace, terrain, and fitness level will differ somewhat from that population average, sometimes meaningfully so at the extremes of pace or fitness. This is a genuine, unavoidable limitation of any population-average-based estimation method, not a flaw specific to MET values, and it's exactly why MET-based calorie estimates are best treated as a reasonable, well-researched approximation rather than a precise, personalized measurement — useful for planning and general comparison, but not a substitute for direct physiological measurement (like a lab-based metabolic test or a well-calibrated heart-rate-based fitness tracker) when genuine individual precision matters.