“Eat less, move more” is technically true, but it’s useless advice without a number attached to it. That number is your TDEE — Total Daily Energy Expenditure — and it’s the single most important figure for anyone trying to lose fat, build muscle, or simply maintain their current weight intentionally rather than by accident.
Here’s how to calculate yours and what to actually do with it.
What Is TDEE? (Total Daily Energy Expenditure Explained)
TDEE is the total number of calories your body burns in a day, combining your resting metabolism with everything else — walking, exercising, digesting food, even fidgeting. The National Institutes of Health’s weight management resources describe this as a far more useful number than a generic “2,000 calories a day” guideline, because it’s personalized to your body and activity level.
The TDEE Formula: BMR × Activity Multiplier
TDEE is calculated in two steps.
Step 1: Calculate your BMR (Basal Metabolic Rate) using the Mifflin-St Jeor equation, widely considered more accurate than older formulas:
- Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
- Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Step 2: Multiply BMR by an activity factor:
- Sedentary (little/no exercise): × 1.2
- Lightly active (1–3 days/week): × 1.375
- Moderately active (3–5 days/week): × 1.55
- Very active (6–7 days/week): × 1.725
- Extremely active (physical job + training): × 1.9
Real TDEE Example — 175 lb, 5’10”, 32-Year-Old Male, Moderate Activity
Let’s convert and calculate:
- Weight: 175 lb ≈ 79.4 kg
- Height: 5’10” ≈ 177.8 cm
- Age: 32
BMR = 10(79.4) + 6.25(177.8) − 5(32) + 5 = 794 + 1,111 − 160 + 5 = ~1,750 calories/day
Applying the moderate activity multiplier (1.55):
TDEE = 1,750 × 1.55 = ~2,713 calories/day
That’s the number of calories this person burns on an average day — and therefore roughly how much they’d need to eat to maintain their current weight.
Using TDEE for Weight Loss (Calorie Deficit)
To lose weight, you eat below your TDEE. A safe, sustainable deficit is typically 500 calories/day, which produces roughly 1 lb of weight loss per week (since 1 lb of fat ≈ 3,500 calories).
For our example: 2,713 − 500 = ~2,213 calories/day for steady, sustainable fat loss.
Using TDEE for Muscle Gain (Calorie Surplus)
To build muscle, you eat above your TDEE, typically by 300–500 calories/day, combined with resistance training. For our example, that’s roughly 3,000–3,200 calories/day — enough to support muscle growth without excessive fat gain.
Why Your TDEE Changes Over Time
TDEE isn’t fixed. It shifts as your weight, muscle mass, age, and activity level change. As you lose weight, your TDEE typically decreases (a smaller body burns fewer calories), which is exactly why weight loss often stalls without adjustment — the “moving target” problem. Recalculating your TDEE every 10–15 lbs of change (or every few months) keeps your calorie target accurate.
Get your personalized TDEE in seconds. Use the TDEE Calculator →
Frequently Asked Questions
What is a good TDEE number?
There’s no universal “good” TDEE — it’s simply a reflection of your body size and activity level. A higher TDEE isn’t better or worse; it just means you burn (and can eat) more calories while maintaining your current weight.
Should I eat my TDEE to lose weight?
No — eating exactly at your TDEE maintains your current weight. To lose weight, you need to eat below your TDEE (a calorie deficit); to gain weight or build muscle, you eat above it (a calorie surplus).
How accurate are TDEE calculators?
TDEE calculators provide a solid estimate — typically within 10–15% of your true number — but individual metabolism varies. The CDC’s guidance on energy balance recommends treating the number as a starting point and adjusting based on real-world results over 2–3 weeks.
Does TDEE change with age?
Yes. Metabolic rate generally declines gradually with age, partly due to natural muscle loss, which is why the same activity level and body weight can require slightly fewer calories at 50 than at 25.