Find your daily calorie needs (TDEE) and basal metabolic rate using the Mifflin-St Jeor formula.
This calculator uses the Mifflin-St Jeor equation — the most validated formula for estimating Basal Metabolic Rate (BMR), the calories your body burns at complete rest. The equations are:
Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
BMR is then multiplied by an activity factor to estimate Total Daily Energy Expenditure (TDEE): Sedentary ×1.2, Lightly active ×1.375, Moderately active ×1.55, Very active ×1.725, Extremely active ×1.9. For weight loss, subtract 500 kcal/day from TDEE for approximately 0.5 kg/week of fat loss. For weight gain, add 300–500 kcal. These are estimates — individual metabolism varies, and tracking actual weight change over 2–3 weeks gives the most accurate personal baseline.
The average adult needs roughly 1,600–2,400 kcal per day for women and 2,000–3,000 kcal for men, depending on age, height, weight, and activity level. Use the Mifflin-St Jeor formula with your activity multiplier for a personalised estimate.
TDEE stands for Total Daily Energy Expenditure — the total calories you burn in a day including your basal metabolic rate plus physical activity. Eating at your TDEE maintains your current weight. Eating below it causes fat loss; above it causes weight gain.
A deficit of 500 kcal per day below your TDEE leads to approximately 0.5 kg (1 lb) of fat loss per week. Deficits larger than 1,000 kcal/day are not recommended as they increase muscle loss and are hard to sustain.
Calorie calculators provide estimates based on averages. Individual metabolism can vary by up to 15% from predicted values. Use the calculator as a starting point, then adjust based on real weight change over 2–4 weeks.