About the Calorie Calculator
Count the calories your body actually needs. This calorie calculator uses the Mifflin-St Jeor equation — the formula dietitians trust most — to estimate your BMR and daily burn (TDEE), then sets a science-based calorie target for losing, maintaining, or gaining weight, complete with a suggested protein, carb, and fat split.
Your age, weight, height and goals are used only in your browser. They are not uploaded, not stored, and not used to sell you anything.
Results are estimates for general information only and are not medical advice. Talk to a healthcare professional before making significant changes to your diet or exercise.
How to use it
- Enter your age, sex, height and weight.
- Choose your activity level.
- Set your goal — maintain, lose or gain.
- Read your daily calorie target.
How the target is built
Your BMR is calculated first using the Mifflin-St Jeor equation, then multiplied by an activity factor to give TDEE — the calories you burn on a typical day.
A goal then adjusts that figure. A deficit of about 500 kcal a day is the common starting point for weight loss, corresponding to roughly half a kilogram a week.
A worked example
A moderately active 32-year-old male, 78 kg, 175 cm:
- BMR: 1,719 kcal
- TDEE at ×1.55: 2,664 kcal
- With a 500 kcal deficit: 2,164 kcal a day
Where the half-kilogram figure comes from: roughly 3,500 kcal is stored in half a kilogram of body fat, and 500 × 7 = 3,500. It is a useful approximation, not a law — real rates vary with water balance, glycogen and adherence.
Common mistakes
- Overstating activity level, which inflates the target and quietly erases the deficit.
- Cutting far below TDEE for fast results, which tends to cost lean mass and rarely lasts.
- Never recalculating. As weight falls, both BMR and TDEE fall with it.
Questions people ask
How fast should I expect to lose weight?
Around 0.5–1% of bodyweight per week is a commonly cited sustainable range. Faster loss increasingly comes from lean tissue and water.
Why has my progress stalled?
A lower body weight burns fewer calories, so the original deficit shrinks over time. Recalculating every few kilograms keeps the target honest.
Is this medical advice?
No. It is an estimate from a standard equation. Anyone with a medical condition, or who is pregnant or breastfeeding, should speak to a clinician before changing intake.