TDEE Calculator is a free online tool that helps you estimate your Total Daily Energy Expenditure (TDEE) — the total calories your body burns in a day. Knowing your TDEE is the starting point for losing weight, gaining muscle, or maintaining your current weight. Our calculators use established, peer-reviewed formulas (Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle) and run entirely in your browser — your numbers never leave your device. The site is maintained by Sonia Kanwal. Important: all results are estimates for educational purposes and are not medical advice. Consult a qualified professional before making major diet changes.