Understanding your calorie needs is the foundation of any nutrition plan. This guide explains the formulas used to calculate your daily calorie requirements.
Basal Metabolic Rate (BMR)
BMR is the number of calories your body burns at complete rest — just to keep you alive (breathing, circulation, cell repair).
Mifflin-St Jeor Equation (Most Accurate)
Men:
BMR = (10 × weight kg) + (6.25 × height cm) - (5 × age) + 5
Women:
BMR = (10 × weight kg) + (6.25 × height cm) - (5 × age) - 161
Example: 30-year-old woman, 65 kg, 165 cm:
BMR = (10 × 65) + (6.25 × 165) - (5 × 30) - 161
BMR = 650 + 1031.25 - 150 - 161 = 1,370 calories
Total Daily Energy Expenditure (TDEE)
TDEE is BMR adjusted for your activity level:
| Activity Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Desk job, little exercise |
| Lightly active | 1.375 | Exercise 1–3 days/week |
| Moderately active | 1.55 | Exercise 3–5 days/week |
| Very active | 1.725 | Hard exercise 6–7 days/week |
| Extremely active | 1.9 | Physical job + hard daily exercise |
Example continued: TDEE for lightly active woman:
TDEE = 1,370 × 1.375 = 1,884 calories/day
Calorie Targets by Goal
| Goal | Calorie Intake |
|---|---|
| Lose weight (slow) | TDEE - 250 |
| Lose weight (moderate) | TDEE - 500 |
| Maintain weight | TDEE |
| Gain muscle (slow) | TDEE + 250 |
| Gain muscle (fast) | TDEE + 500 |
A deficit/surplus of 500 calories per day = roughly 0.5 kg (1 lb) change per week.
Calories in Macronutrients
| Macronutrient | Calories per gram |
|---|---|
| Carbohydrates | 4 kcal |
| Protein | 4 kcal |
| Fat | 9 kcal |
| Alcohol | 7 kcal |
Example: A meal with 40g carbs, 25g protein, 15g fat:
Carbs: 40 × 4 = 160
Protein: 25 × 4 = 100
Fat: 15 × 9 = 135
Total: 395 calories
Important Notes
- Calorie calculators give estimates, not exact values
- Individual metabolism varies by up to 15%
- Track for 2–3 weeks and adjust based on actual results
- Don't drop below 1,200 calories (women) or 1,500 (men) without medical supervision
Use our Calorie Calculator to find your BMR and TDEE based on your stats and activity level.