Understanding BMR and TDEE
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest. Your Total Daily Energy Expenditure (TDEE) is your BMR multiplied by your activity level — the true number of calories you burn each day. Eating at your TDEE maintains your weight.
The Mifflin-St Jeor Equation (2026 Standard)
Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161
TDEE = BMR × Activity MultiplierCalorie Targets for Your Goal
- Weight Loss: TDEE − 500 cal/day ≈ 1 lb/week loss
- Maintenance: Eat at TDEE
- Muscle Gain: TDEE + 300 cal/day (lean bulk)
Frequently Asked Questions
Total Daily Energy Expenditure (TDEE) is the total number of calories you burn in a day, accounting for your basal metabolic rate plus your activity level. It is the number of calories you need to eat to maintain your current weight. To lose weight, eat below TDEE; to gain, eat above it.
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to maintain basic functions: breathing, circulation, cell repair, and temperature regulation. BMR accounts for about 60–70% of your total calorie burn. Our calculator uses the Mifflin-St Jeor equation, the most accurate formula for most people.
A calorie deficit of 500 calories per day results in approximately 1 pound of fat loss per week (since 3,500 calories ≈ 1 lb of fat). Our calculator recommends TDEE minus 500 for weight loss. Do not go below 1,200 calories (women) or 1,500 calories (men) without medical supervision.
BMR (men) = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. BMR (women) = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161. TDEE = BMR × activity multiplier (1.2 to 1.9).
Macros (macronutrients) are protein, carbohydrates, and fat. General guidelines: Protein: 0.7–1g per pound of body weight (4 cal/g). Fat: 25–35% of total calories (9 cal/g). Carbs: remaining calories (4 cal/g). Higher protein is recommended for weight loss (preserves muscle) and muscle gain.
The Mifflin-St Jeor formula is accurate within 10% for most adults. Factors that reduce accuracy: very high or low body fat %, muscle-heavy athletes, and hormonal conditions. Treat the result as a starting point — track your actual weight for 2–4 weeks and adjust ±100–200 calories based on results.
Sedentary (desk job, no exercise): × 1.2. Lightly active (1–3 days/week exercise): × 1.375. Moderately active (3–5 days/week): × 1.55. Very active (6–7 days/week intense): × 1.725. Extra active (physical job + exercise or 2× daily training): × 1.9. Most people overestimate their activity level — when in doubt, go one level lower.
A caloric surplus of 250–500 calories above TDEE supports muscle gain while minimizing fat gain. Pair with adequate protein (0.8–1g per pound body weight) and progressive resistance training. Gaining 0.5–1 lb/week is a realistic and sustainable rate for muscle building.