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What Is TDEE? Total Daily Energy Expenditure Explained
Reviewed by Sarah Mitchell, BSc Nutrition · Updated June 2026 · 8 min read
TDEE — Total Daily Energy Expenditure — is the total number of calories your body burns in 24 hours. It's the single most important number for anyone trying to lose fat, gain muscle, or maintain their weight. Everything else — calorie targets, deficits, surplus — flows from this number.
The simple rule: Eat below your TDEE to lose weight. Eat at your TDEE to maintain. Eat above to gain muscle. The difference between these states is typically 300–600 kcal/day.
The Four Components of TDEE
💡 Key insight: Your BMR accounts for 60–75% of your total calorie burn. Even on a rest day with no exercise, your body burns the majority of its calories just keeping you alive — which is why crash diets that cut calories too aggressively trigger metabolic adaptation.
Component
Abbreviation
% of TDEE
Description
Basal Metabolic Rate
BMR
60–70%
Calories burned at complete rest — breathing, organ function, cell repair
Thermic Effect of Food
TEF
8–10%
Energy used to digest, absorb, and process food
Exercise Activity Thermogenesis
EAT
5–15%
Calories burned during planned exercise
Non-Exercise Activity Thermogenesis
NEAT
15–30%
All movement outside formal exercise: walking, fidgeting, housework
NEAT is the most variable component — it can differ by up to 2,000 kcal/day between two people of the same weight. This is why some people seem to "eat anything" without gaining weight: they unconsciously move more throughout the day.
TDEE breakdown for a moderately active adult (TDEE ~2,500 kcal)
How to Calculate Your TDEE
The most widely validated formula is the Mifflin-St Jeor equation, which estimates BMR and then multiplies by an activity factor:
The result is your estimated TDEE — the number of calories to eat to maintain your current weight. Use our Calorie Calculator to get this number instantly.
How to Use TDEE for Weight Loss
Once you know your TDEE, setting a calorie target is straightforward:
Aggressive fat loss: TDEE − 700 to 1,000 kcal (higher muscle loss risk)
Maintenance: Eat at TDEE
Muscle gain: TDEE + 200 to 400 kcal (lean bulk)
Your TDEE changes as you lose weight — a lighter body needs fewer calories. Recalculate every 4–6 weeks or after every 3–5kg of weight change to keep your targets accurate.
⚠️ TDEE calculators provide estimates, not exact measurements. Individual variation of ±10–15% is normal. Use your initial calculation as a starting point, then adjust based on actual results after 2–3 weeks.
TDEE by Age and Sex: What to Expect
TDEE varies significantly by age, sex, body size, and activity level. The table below shows typical ranges for healthy adults based on the Mifflin-St Jeor formula at a moderate activity level (factor 1.55):
Profile
Sedentary TDEE
Moderate Activity TDEE
Very Active TDEE
Woman, 25, 60 kg, 165 cm
~1,500 kcal
~1,950 kcal
~2,350 kcal
Woman, 45, 65 kg, 165 cm
~1,430 kcal
~1,870 kcal
~2,240 kcal
Man, 25, 80 kg, 178 cm
~1,940 kcal
~2,530 kcal
~3,040 kcal
Man, 45, 85 kg, 178 cm
~1,890 kcal
~2,460 kcal
~2,960 kcal
Man, 65, 78 kg, 175 cm
~1,700 kcal
~2,210 kcal
~2,660 kcal
Two key patterns emerge: (1) Men have higher TDEEs than women at comparable size due to greater lean mass; (2) TDEE decreases with age — approximately 1–2% per decade after 30 — because muscle mass and BMR both decline. This is why the same diet that maintained weight at 25 may cause gradual gain at 45.
💡 For your personalised TDEE based on your exact height, weight, age, and activity level, use our BMR CalculatorCalorie Calculator.
Why Your Real-World TDEE May Differ from Your Calculated TDEE
TDEE calculators are accurate on average, but several factors can cause your actual calorie burn to differ from the estimate by 10–20%:
Metabolic adaptation: After periods of caloric restriction, the body reduces TDEE through reduced NEAT (unconscious movement), lower thyroid output, and improved metabolic efficiency. This is why weight loss slows on a sustained deficit even with accurate tracking.
Gut microbiome: Research shows that different gut bacteria extract different amounts of energy from the same food, causing real-world calorie absorption to vary by up to 10% between individuals.
Inaccurate activity estimates: Most people overestimate their activity level when selecting the multiplier. If in doubt, choose the lower activity category and adjust up based on results.
Medication effects: SSRIs, beta-blockers, corticosteroids, and some diabetes medications can affect metabolic rate and appetite regulation, shifting actual TDEE from predictions.
The most reliable approach: treat your calculated TDEE as a starting point, track food intake consistently for 2–3 weeks, and adjust your calorie target by 100–200 kcal based on whether your weight moves as expected.
Frequently Asked Questions
TDEE (Total Daily Energy Expenditure) is the total calories your body burns in a day. It is calculated by multiplying your BMR (Basal Metabolic Rate — calories burned at rest) by an activity factor ranging from 1.2 (sedentary) to 1.9 (very active). Eating at your TDEE maintains your weight; eating below it creates a deficit for fat loss.
BMR is the calories your body burns at complete rest — just to breathe, maintain organ function, and circulate blood. It typically accounts for 60–75% of TDEE. TDEE adds your physical activity on top of BMR. If you did nothing but lie still all day, you would still burn your BMR in calories.
TDEE calculators using the Mifflin-St Jeor equation are accurate to within 10–15% for most healthy adults. Individual variation exists due to genetics, gut microbiome, thyroid function, and medication effects. The calculated TDEE is best treated as a starting point — adjust based on 2–4 weeks of real-world results.
Yes — as you lose weight, your BMR decreases (a lighter body requires fewer calories at rest) and your activity-related calorie burn also decreases (moving a lighter body uses less energy). This is why recalculating your TDEE every 5–10 kg lost is important — the deficit that worked early on may become maintenance or even a surplus later.
Subtract 300–500 kcal from your TDEE to create a fat loss deficit. Eat at least 1.6–2g of protein per kg of body weight to preserve muscle. Include resistance training 2–4 times per week. Recalculate TDEE every 4–8 weeks at your new body weight. Avoid deficits larger than 750 kcal/day, which accelerate muscle loss.