Calories Burned Calculator

Energy cost scales directly with body weight, so the same walk costs a 90 kg person about 29 % more than a 70 kg one. Measure by time and the calculator uses the activity's MET intensity; measure by distance and it uses the gross cost per kilogram and kilometre. Both are estimates within roughly 15 %.

The number is the gross energy an activity costs. Gross means it includes the resting metabolism you would have spent anyway, which is what trackers and calorie tables report as well; for a net figure, subtract roughly 1 kcal per minute. Two formulas sit behind it. Measured by time, the calculator uses the activity's MET intensity: MET × 3.5 × kilograms ÷ 200 × minutes. With the preset values — walking, 30 minutes, 70 kg — walking's 3.5 MET gives 3.5 × 3.5 × 70 ÷ 200 × 30, or 129 kcal. Measured by distance it uses a gross cost per kilogram and kilometre instead: 5 km walked at 70 kg and 0.53 kcal per kilogram and kilometre comes to 186 kcal. Body weight is the largest single factor in both, entering as a plain multiplier, so the same walk costs a 90 kg person about 29 % more than a 70 kg one. The activity matters more than the distance: at 70 kg the table gives 1026 kcal for 5 km swum and 98 kcal for 5 km cycled. The caveat that matters most is what these figures are. MET values are population averages from laboratory studies, so expect about ±15–20 % for any one person, and terrain, load, efficiency and temperature all shift the real number. The costs per kilometre are approximations rather than published constants.