If you've been trying to lose, gain, or maintain weight and nothing seems to be working, there's a good chance you don't know your TDEE — or you've calculated it incorrectly. TDEE is Total Daily Energy Expenditure, and it's the single most important number in any nutrition plan. Once you know it, the mystery of "why am I not losing weight?" usually dissolves very quickly.
What Is TDEE?
TDEE is the total number of calories your body burns in a typical day — accounting for everything: keeping your organs running, walking to the kitchen, your gym session, and even the energy used to digest food. It is, in short, your maintenance calorie level. Eat at your TDEE and your weight stays roughly stable. Eat below it and you lose weight. Eat above it and you gain.
Our calorie deficit calculator uses your TDEE to help you set an appropriate calorie target for weight loss or gain.
TDEE vs BMR: What's the Difference?
BMR — Basal Metabolic Rate — is the number of calories your body needs at complete rest. It's the energy required just to exist: breathing, pumping blood, maintaining temperature, running your organs. BMR typically accounts for 60-75% of total energy expenditure.
TDEE is your BMR multiplied by an activity factor. It's the complete picture. Confusingly, some apps and tools show you your BMR and call it your "daily calorie need" — which would mean eating as if you're bedridden. This error leads to significant undereating. Always check whether a number is BMR or TDEE before using it as your target.
The Four Components of TDEE
- BMR (Basal Metabolic Rate): ~60-75% of TDEE — the resting baseline
- TEF (Thermic Effect of Food): ~10% — energy used to digest, absorb and metabolise food
- EAT (Exercise Activity Thermogenesis): calories burned during intentional exercise
- NEAT (Non-Exercise Activity Thermogenesis): calories burned during all other movement — walking, fidgeting, standing, household tasks
NEAT is often overlooked but hugely variable. Someone with an active job (a nurse, a builder) might burn 500-1,000 more calories per day through NEAT than a desk worker — without any formal exercise. This is why "I go to the gym three times a week" doesn't automatically mean you're "very active" overall.
How to Calculate Your TDEE
Step 1 is to estimate your BMR. The Mifflin-St Jeor equation is generally considered the most accurate for most people:
- 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
Step 2: Multiply by your activity factor (see the calorie calculator article for these values). Use our calorie calculator to handle all of this automatically.
The Accuracy Problem — And How to Solve It
TDEE formulas are estimates derived from population averages. Your actual TDEE might be 10-15% higher or lower than the formula predicts, depending on your individual metabolism, muscle mass, hormonal factors, and habits you don't even realise you have (like how much you fidget).
The most accurate way to find your true TDEE is empirically: track your food intake meticulously for 2-3 weeks while keeping your weight stable. The average calories you ate during that period is your actual TDEE. This is far more accurate than any formula.
Using TDEE for Weight Loss
A 500-calorie daily deficit below your TDEE creates a 3,500-calorie weekly deficit — roughly equivalent to 0.5kg (1lb) of fat loss per week. A 250-calorie deficit creates about 0.25kg per week. These are approximate figures (the "3,500 calories = 1 pound" rule is a simplification), but they're reliable enough for planning purposes.
Don't create too large a deficit — below about 1,200 calories (women) or 1,500 calories (men) you risk losing muscle mass, nutrient deficiencies, and metabolic adaptation. Sustainable is better than extreme.
TDEE for Weight Gain (Building Muscle)
For muscle building, eat 200-500 calories above TDEE. More than that and you'll gain fat faster than muscle. Gaining muscle is a slow process — expecting to gain more than 0.5-1kg per month without also gaining fat is unrealistic for most natural trainees.
Know your TDEE, set your target sensibly, track your intake, and adjust based on real results. That's the entire formula for successful body composition management.
Further reading: Healthline has a detailed, evidence-based article on TDEE and how to use it. Read Healthline's guide to TDEE.