How the Calorie Calculator Works
This calculator uses the Mifflin-St Jeor equation — the most accurate BMR formula for most people — to calculate your Basal Metabolic Rate (BMR), then multiplies it by your activity level to find your TDEE.
Mifflin-St Jeor BMR Formula
Male: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Female: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
What is TDEE?
Total Daily Energy Expenditure (TDEE) is the total calories your body burns per day, accounting for activity. It's your maintenance calorie level — eat below it to lose weight, above it to gain.
Calorie Targets by Goal
Weight loss: A 500 calorie/day deficit leads to approximately 0.5kg (1 lb) of fat loss per week. For faster loss, a 1,000 cal/day deficit targets ~1kg/week, but should be done with medical guidance.
Muscle gain: A 300–500 calorie surplus combined with resistance training supports lean muscle building.
FAQs
How many calories should I eat to lose weight?
To lose weight, eat below your TDEE. A deficit of 500 calories/day leads to roughly 0.5kg (1 lb) loss per week. The calculator shows your exact weight-loss calorie target above.
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to maintain vital functions — breathing, circulation, cell production. It's typically 60–70% of total calorie burn.
Is 1200 calories a day enough?
1200 calories/day is generally considered the minimum safe intake for women. Men typically need at least 1500 calories. Going below these levels can cause nutrient deficiencies and metabolic adaptation. Always consult a doctor before very low calorie diets.
How accurate is this calculator?
The Mifflin-St Jeor formula is accurate to within 10% for most people. Results are estimates — actual needs vary with genetics, health conditions, and more. Use it as a starting point and adjust based on real-world results.