Calorie Calculator (BMR & TDEE)

Work out how many calories your body burns in a day, and how much to eat to lose fat, maintain or gain lean muscle.

Sex
yrs
cm
kg

Enter your details to see your result.

How the calorie calculator works

First we estimate your Basal Metabolic Rate (BMR) — the energy your body uses at complete rest — with the Mifflin–St Jeor equation, the most accurate formula for most adults in clinical studies.

MenBMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
WomenBMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161

Then we multiply BMR by an activity factor to get your Total Daily Energy Expenditure (TDEE) — what you burn on an average day, including training, work and daily movement.

Activity levelFactor
Sedentary · desk job, no training× 1.2
Light · 1–3 workouts a week× 1.375
Moderate · 3–5 workouts a week× 1.55
Very active · 6–7 workouts a week× 1.725
Athlete · twice a day or a physical job× 1.9

Reading your result

Maintenance (TDEE) keeps your weight stable. For fat loss we suggest 20% below TDEE — enough for steady progress of about 0.5–1% of body weight a week without hurting training. For lean muscle gain we suggest 10% above TDEE to limit fat gain.

Targets never go below 1,500 kcal for men or 1,200 kcal for women; eating less than that makes it hard to meet your nutrient needs without medical supervision.

Tips & limitations

  • Treat the number as a starting point. Track your weight for 2–3 weeks and adjust by 100–200 kcal if it isn’t moving the way you want.
  • Most people overestimate their activity. If unsure, pick the lower level.
  • Recalculate after every 4–5 kg of weight change — your needs change as your body does.
  • Hit your protein target first; it keeps you full and protects muscle while dieting.

Frequently asked questions

What is the difference between BMR and TDEE?

BMR is the energy your body needs at complete rest to keep you alive. TDEE adds everything else — digestion, walking, work and exercise — and is the number you eat around.

How many calories should I eat to lose weight?

Start at about 20% below your TDEE. For most people that means losing roughly 0.5–1% of body weight per week, which preserves muscle and energy for training.

How many calories should I eat to build muscle?

Around 10% above your TDEE, with enough protein (about 1.6–2.2 g per kg of body weight). Larger surpluses mostly add fat, not extra muscle.

Why is my result different from my fitness tracker?

Trackers estimate exercise calories from heart rate and often overcount them. Equation-based estimates are usually more reliable for setting a daily intake — your weight trend over a few weeks is the final judge.

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These calculators give estimates for general fitness guidance only and aren’t medical advice. Speak to a doctor before making major diet or training changes, especially if you are pregnant, under 18 or have a medical condition.