To lose about 1 pound (0.45 kg) of fat per week, eat roughly 500 calories per day below your TDEE (Total Daily Energy Expenditure). Since one pound of fat is roughly 3,500 calories, a 500-calorie daily deficit adds up to that loss over 7 days. This calculator works out your personal number from your BMR and activity level.

For muscle gain, most people do best eating 200-300 calories above their TDEE per day — a “lean bulk” — paired with roughly 1.6-2.0 grams of protein per kilogram of bodyweight and progressive resistance training. A bigger surplus does not build muscle faster, it mostly adds fat.

TDEE stands for Total Daily Energy Expenditure — the total calories your body burns in a day including activity. It starts from your BMR (calories burned at rest, estimated using the Mifflin-St Jeor equation) multiplied by an activity factor based on how active you are.

Research generally supports 1.6 to 2.2 grams of protein per kilogram of bodyweight per day for muscle growth, spread across meals. This calculator estimates a personal daily target from your bodyweight.

Yes. Every calculator on this page is free, requires no signup, and calculates instantly in your browser.

It is an educational estimate built from the established Mifflin-St Jeor formula and published research on macronutrients and muscle growth, not a medical or clinical measurement. A coach or dietitian can help you fine-tune it for your body.