Estimate how many calories an activity burns based on your body weight, how long you do it, and the intensity of the activity. Pick an activity from the list, which sets its MET value (metabolic equivalent, a standard measure of intensity), enter your weight and the duration in minutes, and the calculator uses the established formula of MET times body weight in kilograms times hours to give an estimate in calories. Heavier bodies and harder activities burn more, which is exactly what the formula captures. These are population averages, so your real burn depends on fitness, efficiency and effort, but they are reliable enough for comparing activities and planning. Use them alongside a calorie target rather than as an exact reading. Everything is computed locally in your browser.