Daily Calorie Calculation (TDEE Method)

Daily calorie needs are calculated in two steps: determine Basal Metabolic Rate (BMR), then multiply by an activity factor to get Total Daily Energy Expenditure (TDEE).

Step 1: Calculate BMR — Mifflin-St Jeor Equation

Men:   BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(years) + 5
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(years) − 161

Example: 30-year-old male, 80 kg, 180 cm: BMR = 10×80 + 6.25×180 − 5×30 + 5 = 1,805 kcal

Step 2: Multiply by Activity Factor

Activity Level	Multiplier
Sedentary (desk job, no exercise)	1.2
Lightly active (exercise 1–3 days/week)	1.375
Moderately active (exercise 3–5 days/week)	1.55
Very active (exercise 6–7 days/week)	1.725
Extremely active (physical job + daily training)	1.9

Example (continued): Moderately active: TDEE = 1,805 × 1.55 ≈ 2,798 kcal/day

Step 3: Adjust for Goal

• Maintenance: eat at TDEE
• Weight loss: TDEE − 500 kcal (yields ~0.5 kg / 1 lb loss per week)
• Weight gain: TDEE + 250–500 kcal

Standard Macronutrient Split

• Protein: 10–35% of calories (4 kcal/g)
• Carbohydrates: 45–65% (4 kcal/g)
• Fat: 20–35% (9 kcal/g)

Notes

• Formulas are estimates; real expenditure varies by body composition, genetics, and thermic effect of food.
• Recalculate after every ~5 kg weight change.
• Alternative formula: Katch-McArdle (BMR = 370 + 21.6 × lean mass in kg) is more accurate if body fat percentage is known.
• Consult a healthcare professional before significant dietary changes, especially with medical conditions.