TDEE Calculator is a free tool that estimates how many calories you burn in a day from your age, height, weight and activity, using the Mifflin-St Jeor equation dietitians rely on. It then sets cut, maintain and gain targets plus a protein-first macro split. The maths runs in your browser and nothing is uploaded.
How to estimate your calorie needs
- Pick Metric or Imperial units, then enter Age, Height and Weight.
- Choose the Activity that matches a typical week, not your best one.
- Read To maintain weight — that is your TDEE — and pick a target below or above it.
- Use the macro split as a starting template for protein, fat and carbs.
A worked example: 80 kg, 180 cm, 30 years old
The equation gives a resting burn of 1,780 kcal a day (10 × 80 plus 6.25 × 180, minus 5 × 30, plus 5 for men). At a Moderate activity factor of 1.55 that becomes 2,759 kcal to maintain weight. The steady-loss target is therefore about 2,509 kcal and the faster cut about 2,259 — numbers you can verify on paper, which is the point.
The activity trap that ruins most estimates
Three gym sessions around a desk job is Moderate, not Active, and the gap between those two settings is over 300 kcal a day — a whole meal's worth of phantom budget. When in doubt, take the lower setting for two weeks and adjust from the scale, not from optimism. For the other half of the picture, check where your weight sits today with the BMI Calculator, and protect the recovery that diets depend on with the Sleep Cycle Calculator.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is what your body burns at complete rest to stay alive. TDEE multiplies that by an activity factor from 1.2 to 1.9, so it is the number your eating should be judged against.
Which activity level should I pick?
One lower than your instinct. Most people count a good week instead of a typical one: desk work with three gym sessions is Moderate, not Active. Overestimating here is the most common reason calorie targets fail.
How fast will I lose weight on the cut target?
The 500-calorie daily deficit aims at roughly 0.5 kg a week, and the milder 250 deficit at half that. Real loss varies with water, sleep and how honestly intake is tracked — weigh weekly, not daily.
Is this medical or diet advice?
No. It is a planning estimate from a published formula, using the averages it was built on. It knows nothing about your health history, medication or training, so treat the result as a starting point for a professional conversation.
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