Calories Burned Calculator
Calories burned by activity, from your weight and how long you kept at it.
How the estimate works
Every activity has a MET value, its energy cost as a multiple of sitting at rest, measured across thousands of people in the Compendium of Physical Activities. Calories burned = MET × weight in kg × hours. Brisk walking at 5 METs burns a 72 kg person about 360 kcal per hour; running at 10 km/h nearly doubles that.
Why heavier people burn more
Moving more mass costs more energy, so the same walk burns proportionally more calories at a higher body weight. This is also why the number falls as you lose weight and why fitness trackers ask for your weight. The figures here are averages: individual economy, terrain and intensity swing the true number by ±20% or more.
Exercise burns less than people hope
A 45-minute gym session for a 72 kg person is typically 250 to 450 kcal, roughly one pastry. Exercise is excellent for fitness, health and keeping weight off, but the deficit that drives weight loss is far easier to create in the kitchen. The calorie deficit calculator does that arithmetic.