How Many Calories Do You Need Per Day? TDEE Guide
6 min read · Updated 2025
Whether you want to lose weight, build muscle, or just maintain your current weight, understanding your daily calorie needs is the foundation. This guide explains TDEE (Total Daily Energy Expenditure) — the scientific way to calculate exactly how many calories you burn each day.
Step 1: Calculate Your BMR
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest — just to keep your organs functioning. The most accurate formula is the Mifflin-St Jeor equation:
Men: BMR = 10W + 6.25H − 5A + 5
Women: BMR = 10W + 6.25H − 5A − 161
W = weight (kg) | H = height (cm) | A = age (years)
Example: A 30-year-old woman, 60 kg, 165 cm: BMR = (10 × 60) + (6.25 × 165) − (5 × 30) − 161 = 600 + 1031.25 − 150 − 161 = 1,320 kcal/day
Step 2: Multiply by Activity Level (Get Your TDEE)
| Activity Level | Description | Multiplier |
|---|---|---|
| Sedentary | Little or no exercise, desk job | × 1.2 |
| Lightly active | Light exercise 1–3 days/week | × 1.375 |
| Moderately active | Moderate exercise 3–5 days/week | × 1.55 |
| Very active | Hard exercise 6–7 days/week | × 1.725 |
| Extremely active | Physical job + hard training | × 1.9 |
Using our example: 1,320 × 1.375 (lightly active) = 1,815 kcal/day TDEE. This is how many calories she needs to maintain weight.
Calorie Goals for Different Targets
Lose Weight
TDEE − 500 kcal/day
≈ 0.5 kg/week fat loss
Maintain Weight
Eat = TDEE
No change in body weight
Gain Muscle
TDEE + 250–500 kcal/day
Lean bulk, minimal fat gain
Macronutrient Split
Once you know your calorie target, split it into macronutrients:
- Protein: 1.6–2.2 g per kg of body weight — essential for muscle preservation
- Fat: 20–35% of total calories — critical for hormones and fat-soluble vitamins
- Carbohydrates: Remaining calories — primary fuel for exercise and brain function
Calculate your calorie needs instantly with BrainBoost's Calorie Calculator. Also check the BMI Calculator and Fitness Tracker.