How Many Calories Do I Need Per Day? TDEE & BMR Explained

Understand your daily energy needs: BMR, TDEE, activity levels, and how to use them for weight loss, maintenance, or muscle gain.

Why Knowing Your Calorie Needs Matters

Whether you want to lose weight, gain muscle, or simply maintain your current shape — understanding how many calories your body burns daily is the foundation of any nutrition plan. This guide explains BMR (Basal Metabolic Rate) and TDEE (Total Daily Energy Expenditure) in simple terms.

What is BMR (Basal Metabolic Rate)?

BMR is the number of calories your body needs to maintain basic life functions — breathing, blood circulation, cell production, and temperature regulation — at complete rest. It's the calories you'd burn if you lay in bed all day without moving. BMR accounts for about 60–70% of your total daily calorie burn.

🔑 Factors That Affect BMR

Weight: Heavier people have higher BMR
Height: Taller people have higher BMR
Age: BMR decreases with age
Gender: Men typically have higher BMR due to more muscle mass
Muscle mass: More muscle = higher BMR

The Mifflin-St Jeor Formula

This is the most accurate BMR formula used by nutritionists and researchers today:

👨 For Men

BMR = 10W + 6.25H − 5A + 5

👩 For Women

BMR = 10W + 6.25H − 5A − 161

W = weight in kg, H = height in cm, A = age in years

BMR Calculation Example

Let's calculate BMR for a 30-year-old woman, 165 cm tall, weighing 60 kg:

BMR = (10 × 60) + (6.25 × 165) − (5 × 30) − 161

BMR = 600 + 1031.25 − 150 − 161

✅ BMR ≈ 1,320 kcal/day

This is the energy her body needs just to function — before any movement or exercise.

What is TDEE (Total Daily Energy Expenditure)?

TDEE is your BMR multiplied by an activity factor. It represents the total calories you burn in a day, including all movement, exercise, and even digestion. This is the number you need to know for weight management.

Activity Level	Description	Multiplier
Sedentary	Little or 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
Super Active	Athlete, physical job, training 2×/day	1.9

TDEE Calculation Example

Using our 30-year-old woman with BMR of 1,320 kcal and moderate activity (3–5 days/week):

TDEE = BMR × Activity Multiplier

TDEE = 1,320 × 1.55

✅ TDEE ≈ 2,046 kcal/day

This is the total calories she burns daily — the amount needed to maintain her current weight.

How to Use TDEE for Your Goals

📉 Weight Loss

TDEE − 500 kcal
Lose ~0.5 kg per week

⚖ Maintenance

Eat at TDEE
Weight stays stable

📈 Muscle Gain

TDEE + 300–500 kcal
Gain ~0.25–0.5 kg per week

Key Takeaways

BMR ≠ TDEE: BMR is just your base metabolism — TDEE includes all activity
TDEE is your maintenance number: Eat at TDEE to stay the same weight
500 kcal deficit = ~0.5 kg/week loss: A safe, sustainable rate
Recalculate every 5–10 kg lost: Your TDEE drops as you lose weight
Use our calculator: Manual math is tedious — let our tool do the work

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