Calorie & BMR Calculator

The calculator estimates your Basal Metabolic Rate (BMR) — the energy your body uses at rest — using the Mifflin-St Jeor equation from your age, sex, height and weight, then multiplies it by an activity factor to give your Total Daily Energy Expenditure (TDEE): the calories you burn in a typical day.

BMR is what you'd burn lying in bed all day. TDEE is BMR plus the energy you spend moving, exercising and digesting food. To maintain your weight, eat around your TDEE; to lose or gain, adjust from there.

A deficit of about 500 calories a day below your TDEE leads to roughly 0.5 kg of fat loss per week; a 500-calorie surplus supports a similar rate of gain. Avoid very large deficits, which are hard to sustain and can cost you muscle.

No — they're a well-validated estimate. Real needs vary with muscle mass, genetics and daily activity. Use the number as a starting point, track your weight for 2–3 weeks, and adjust by 100–200 calories if you're not moving in your intended direction.