Calorie Calculator
Find out how many calories your body actually burns per day — and what to eat to maintain, lose or gain weight at a sensible rate.
How the math works
TDEE = BMR × activity factor (1.2 → 1.9)
Your basal metabolic rate (BMR) is what your body burns at complete rest — typically 60–70% of everything you burn in a day. Multiply it by an activity factor and you get your TDEE (total daily energy expenditure): the calories that keep your weight exactly where it is. A kilogram of body fat stores roughly 7,700 kcal, so eating ~550 kcal/day below TDEE loses about 0.5 kg (1 lb) per week; the same surplus above TDEE gains it.
How to use the numbers
Pick one deficit or surplus and hold it for 3–4 weeks, then re-weigh and adjust. Losing faster than ~1% of body weight per week usually costs you muscle, not just fat. And floors matter: going below about 1,200 kcal (women) or 1,500 kcal (men) is not advisable without a doctor supervising — the goal is a diet you can actually keep.
FAQ
- Why do two calculators give me different numbers?
- Formulas differ (Harris-Benedict vs Mifflin-St Jeor) and everyone's metabolism varies ±10%. Use any reasonable estimate as a starting point, then adjust from real-world weigh-ins — your scale outranks any formula.
- Do exercise calories count separately?
- The activity factor already includes your training, so don't subtract workout calories on top — that double-counts.
- Does metabolism slow with age?
- Modestly — mostly via lost muscle. Keeping up resistance training and protein matters more than the formula's age term.
This tool provides general information only and is not medical advice. If you are pregnant, managing a medical condition, or considering a restrictive diet, consult a qualified healthcare professional.