How many calories should I eat? TDEE, explained
Your calorie needs come down to one number: TDEE — Total Daily Energy Expenditure, the calories you burn in a day.
The two pieces
- BMR (Basal Metabolic Rate) — what you’d burn at complete rest. We estimate it with the Mifflin–St Jeor equation, the most validated predictive formula for healthy adults.
- Activity factor (PAL) — a multiplier for how active your day is, from mostly sitting (×1.2) to extremely active (×1.9).
TDEE = BMR × activity factor. That’s your maintenance — eat that, and your
weight stays roughly stable.
From maintenance to a goal
- Lose fat: a modest deficit (we default to about −20%, capped at −25% to protect muscle and adherence).
- Build muscle: a small surplus (~+10%) to minimize fat gain.
- Maintain or recomposition: around maintenance.
These are evidence-based defaults, not rigid rules — individual needs vary, which is why the activity factor is always an estimate.
Get your number
The calorie calculator runs Mifflin–St Jeor for you and applies a goal-appropriate target. Pair it with the macro calculator to split those calories into protein, carbs and fat — then build your full plan to put training and nutrition together.
Estimates from established formulas — not medical advice. Never eat below a safe minimum (~1500 kcal for men, ~1200 for women) without professional guidance.
Sources
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure (1990)
- ISSN Position Stand: Diets and Body Composition
Estimations générales de fitness et nutrition — pas un avis médical.