Estimate your Basal Metabolic Rate (BMR) and daily calorie needs based on your age, gender, height, weight, and activity level.
This calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR) — the number of calories your body burns at complete rest just to maintain basic functions.
Your BMR is then multiplied by an activity factor to estimate your Total Daily Energy Expenditure (TDEE), which reflects the calories you burn in an average day including exercise and daily movement.
Depending on your goal, a calorie adjustment is applied on top of your TDEE: a deficit for weight loss or a surplus for weight gain. These are general estimates — actual needs vary by individual, so consult a healthcare professional for personalized guidance.
It's estimated by calculating your BMR (calories at rest) and multiplying by an activity factor based on how active you are, giving your maintenance calorie level.
Eating below your maintenance calories creates a deficit for weight loss; eating above it creates a surplus for weight gain — roughly 3,500 calories corresponds to about 1 pound of body weight.
Standard formulas use weight, height, age, and sex, not muscle mass directly, so very muscular or very lean individuals may see some inaccuracy.