Understanding Your TDEE: Why 'Eat Less, Move More' Isn't Specific Enough

"Eat less, move more" is technically true but practically useless without a number to work from. Total Daily Energy Expenditure (TDEE) is that number — your actual daily calorie burn, which is what any calorie target for weight loss, maintenance, or gain should be built around.

BMR: the foundation

Basal Metabolic Rate (BMR) is the energy your body burns at complete rest — just keeping your organs running, maintaining body temperature, and other baseline functions. It accounts for the majority of most people's daily energy use, even before any deliberate activity. The Mifflin-St Jeor equation (1990) is the most commonly recommended formula for estimating it today, generally considered more accurate for modern populations than the older Harris-Benedict equation from 1919.

TDEE: BMR plus activity

TDEE takes your BMR and multiplies it by an activity factor reflecting how much you move in a typical day — from sedentary (little to no exercise) up to very active (physical job or twice-daily training). This is your actual maintenance calorie level: eat exactly this much, and your weight should stay roughly stable over time.

Why a flat "2000 calories a day" guideline misses the point

Generic guidelines like "2000 calories a day" are population averages that ignore your specific height, weight, age, gender, and activity level — all of which genuinely change your real number, sometimes by hundreds of calories in either direction. A sedentary 50kg woman and an active 90kg man have wildly different actual energy needs; using the same flat target for both is close to meaningless for either of them.

Setting a realistic deficit or surplus

A commonly cited approach for gradual weight change is a roughly 500 calorie/day deficit (for loss) or surplus (for gain) relative to your TDEE, corresponding to about 0.5kg of change per week — though individual response varies, and anyone with an underlying health condition should consult a doctor or nutritionist before making significant changes.

Calculate your actual number

Our Calorie / TDEE Calculator computes your BMR and TDEE using the Mifflin-St Jeor equation, plus ready-made deficit and surplus targets — so you're working from your own real number, not a generic guess.

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