What is daily calorie need?
Calorie need is the amount of energy your body requires to perform daily functions. It depends on your basal metabolic rate (BMR) and physical activity level. Knowing your calorie needs helps you plan your diet more effectively.
How to calculate calorie needs?
This calculator uses the Mifflin-St Jeor formula, the most widely validated method for estimating BMR:
Men: BMR = 10 × weight(kg) + 6.25 × height(cm) – 5 × age + 5
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) – 5 × age – 161
The older Harris-Benedict equation is also commonly used. For lean individuals who know their body fat percentage, the Katch-McArdle formula — which uses lean body mass directly — is considered more precise.
What is basal metabolic rate (BMR)?
BMR is the number of calories your body burns at rest to maintain vital functions: breathing, heart function, body temperature regulation. BMR accounts for approximately 60–75% of your total daily calorie needs.
How does activity level affect calorie needs?
Total Daily Energy Expenditure (TDEE) is calculated by multiplying BMR by an activity factor:
- Sedentary (×1.2): Desk job, little physical activity
- Light activity (×1.375): Exercise 1–3 times per week
- Moderate activity (×1.55): Exercise 3–5 times per week
- Active (×1.725): Exercise 6–7 times per week
- Very active (×1.9): Intense exercise twice per day
What are some calorie need examples?
30-year-old man: 80 kg, 180 cm, moderately active. BMR = 1,780 kcal. TDEE = 1,780 × 1.55 = 2,759 kcal/day.
25-year-old woman: 60 kg, 165 cm, lightly active. BMR = 1,354 kcal. TDEE = 1,354 × 1.375 = 1,862 kcal/day.
How many calories should I eat to lose weight?
To lose weight, consume fewer calories than you burn. A deficit of 500 kcal/day leads to roughly 0.5 kg of fat loss per week — based on the rule that 1 lb (0.45 kg) of fat contains approximately 3,500 kcal. Women should not eat below 1,200 kcal/day; men, below 1,500 kcal/day.
Calorie quality matters too: 500 kcal from whole foods (vegetables, lean protein, legumes) keeps you fuller and more nourished than 500 kcal from ultra-processed snacks. Focus on nutrient-dense foods, not just hitting a calorie number.
How many calories should I eat to gain muscle?
To gain muscle, eat slightly more calories than your TDEE — a surplus of 200–300 kcal per day is enough to support muscle growth without excessive fat gain. Pair the surplus with adequate protein (1.6–2.2 g per kg of body weight) and progressive resistance training. Larger surpluses do not build muscle faster but do increase fat storage. You can also check our water intake calculator and ideal weight calculator for a fuller picture of your health goals.