What Is TDEE and Why Does It Matter?
Your Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a 24-hour period, including everything from keeping your heart beating to running a 5K. Knowing your TDEE is the foundation of any effective nutrition plan — whether you want to lose fat, build muscle, or simply maintain your weight.
The calculation combines two key variables: your Basal Metabolic Rate (BMR) — calories burned at complete rest — and your Physical Activity Level (PAL), expressed as a multiplier between 1.2 and 2.5.
The TDEE Formula Step by Step
Calculating TDEE is a two-step process:
- Step 1: Calculate your BMR using age, sex, height, and weight
- Step 2: Multiply your BMR by your activity factor
TDEE = BMR × Activity Multiplier
Step 1: Calculate Your BMR
Three formulas are widely used to estimate BMR. The Mifflin-St Jeor equation is considered the most accurate for most adults:
Mifflin-St Jeor Formula (Recommended)
- Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Example: A 30-year-old man, 175 cm tall, weighing 80 kg:
BMR = (10 × 80) + (6.25 × 175) − (5 × 30) + 5 = 800 + 1,093.75 − 150 + 5 = 1,748 kcal/day
Harris-Benedict Formula (Classic)
- Men: BMR = (13.397 × kg) + (4.799 × cm) − (5.677 × age) + 88.362
- Women: BMR = (9.247 × kg) + (3.098 × cm) − (4.330 × age) + 447.593
Katch-McArdle Formula (Most Accurate If You Know Body Fat %)
BMR = 370 + (21.6 × Lean Body Mass in kg)
Where: Lean Body Mass = Total Body Weight × (1 − Body Fat %)
Step 2: Multiply by Your Activity Factor
Once you have your BMR, multiply it by the activity factor that best describes your daily life:
| 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 |
| Extra Active | Physical job + hard exercise daily | × 1.9 |
Example continued: The same man with moderate activity (1,748 × 1.55) = 2,709 kcal/day TDEE
How to Use Your TDEE to Reach Your Goals
Once you know your TDEE, setting your calorie target is straightforward:
- Lose weight: Eat 300–500 kcal below your TDEE per day (safe, sustainable deficit)
- Maintain weight: Eat at your TDEE
- Build muscle: Eat 200–300 kcal above your TDEE (lean bulk)
How Accurate Is the TDEE Formula?
No equation is perfect. Research shows the Mifflin-St Jeor formula is accurate within ±10% for most people. Your real TDEE can vary due to:
- Genetics and metabolic rate differences
- Muscle mass (more muscle = higher TDEE)
- Non-exercise activity thermogenesis (NEAT) — fidgeting, walking around, etc.
- Dietary thermogenesis (protein costs more energy to digest)
For best results, use a calculated TDEE as a starting point and adjust by 100–200 kcal based on real-world weight changes over 2–3 weeks.
Frequently Asked Questions
Can I calculate my TDEE without knowing my body fat?
Yes. The Mifflin-St Jeor and Harris-Benedict formulas only require your age, height, weight, and sex. The Katch-McArdle formula additionally requires body fat percentage but is more accurate for very lean or very heavy individuals.
How often should I recalculate my TDEE?
Recalculate whenever you lose or gain more than 5 kg, or if your activity level changes significantly. Weight changes affect BMR, and activity changes affect the multiplier.
Should I eat exactly at my TDEE every day?
Not necessarily. What matters is your weekly calorie average. You can eat more on workout days and less on rest days, as long as the week averages to your target.