Your Total Daily Energy Expenditure (TDEE) is the number of calories your body burns in a full 24 hours — including sleep, digestion, walking, work, and training. Knowing this number is the single most important step before any cut, bulk, or recomposition. If you don't know your TDEE, every diet you try is a guess.
How the TDEE calculator works (Mifflin-St Jeor)
We use the Mifflin-St Jeor equation, which is the most accurate BMR formula for the general population according to peer-reviewed research. First we compute your Basal Metabolic Rate (BMR) — the calories you'd burn lying in bed all day. Then we multiply BMR by an activity factor (1.2 sedentary → 1.9 very active) to get your TDEE. Formula (men): BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5. Women: subtract 161 instead of adding 5.
BMR vs. TDEE — what's the difference?
BMR is the bare-minimum energy your organs, brain, and cells need just to keep you alive. TDEE is BMR plus everything you actually do — walking, working, training, even fidgeting (NEAT). To lose weight you eat below TDEE (not BMR). To gain muscle you eat above TDEE. Eating below BMR long-term slows metabolism and burns muscle.
How to pick your activity level honestly
Most people overestimate their activity. Sedentary (1.2) = desk job, no gym. Lightly active (1.375) = walking 30–60 min/day or 1–3 easy workouts/week. Moderately active (1.55) = 3–5 hard workouts/week. Very active (1.725) = daily hard training or physical job. Extra active (1.9) = pro athlete or manual labor + training. When in doubt, pick one level lower and adjust after 2 weeks of tracking.
What to do with your TDEE number
Cutting: eat 300–500 kcal below TDEE for a sustainable 0.3–0.5 kg/week loss. Bulking: eat 200–300 kcal above TDEE for lean gain of ~0.25 kg/week. Maintenance / recomp: eat at TDEE and prioritize protein and progressive overload. Recheck your TDEE every 4–6 weeks or after every 3 kg of weight change.
Worked example
A 30-year-old man, 80 kg, 178 cm, trains 4×/week. BMR = 10×80 + 6.25×178 − 5×30 + 5 = 800 + 1112.5 − 150 + 5 = 1767.5 kcal. TDEE at moderate activity (1.55) = 1767.5 × 1.55 ≈ 2740 kcal/day. To lose fat he'd eat ~2340 kcal/day; to bulk lean, ~3000 kcal/day.
- 1Weigh yourself 3–7 mornings/week and average — daily fluctuations lie.
- 2Adjust calories after 2 weeks of no change, not after 2 days.
- 3Protein stays constant across cut/bulk (1.6–2.2 g/kg); adjust carbs first, then fats.
Frequently asked questions
Q1.Is the TDEE calculator 100% accurate?
No calculator is. Expect ±10%. Use it as a starting point, then adjust based on 2-week weight trends.
Q2.Do I have to hit this number exactly every day?
No. What matters is the weekly average. Being ±100 kcal on a given day is normal and irrelevant.
Q3.When should I recalculate?
Every 3–4 weeks, or after your weight has changed by ~3 kg, or if your activity level changes meaningfully.
Q4.Why did I stop losing weight even though I'm eating below TDEE?
Usually one of: underestimated portions, adaptive thermogenesis (metabolism dips slightly), water retention, or NEAT dropping. Recompute and honestly re-track for 7 days.
Q5.TDEE vs. BMR — which do I diet from?
Always diet from TDEE. BMR is the theoretical floor; going below it long-term is unhealthy.
TDEE is an estimate for healthy adults. If you're pregnant, breastfeeding, under 18, over 65, recovering from an eating disorder, or managing diabetes / thyroid disease, consult a physician or registered dietitian before changing your calories.