TDEE Calculator
Total Daily Energy Expenditure — calories burned per day at your real activity level.
TDEE — The Number That Actually Matters
BMR is what your body would burn lying perfectly still. TDEE is the real-world number: BMR plus everything you do — moving, exercising, fidgeting, digesting food, and otherwise being alive. If you eat at your TDEE, your weight is stable. Above it, you gain. Below it, you lose. See Wikipedia on energy homeostasis for the underlying physiology.
The Four Components of TDEE
| Component | Share of TDEE | What It Is |
|---|---|---|
| BMR | 60-70% | Keeping you alive at rest |
| TEF (Thermic Effect of Food) | 5-10% | Digesting food; highest for protein (~25%) |
| NEAT (Non-Exercise Activity) | 15-30% | Walking, fidgeting, standing, posture |
| EAT (Exercise Activity) | 5-15% | Formal workouts only |
Surprising fact: NEAT varies more between individuals than exercise does. Two people doing identical workouts can have TDEEs that differ by 600+ cal/day depending on how much they fidget, stand, walk around the office, etc. Research from the Mayo Clinic (Levine et al., classic 1999 Science paper) showed NEAT differences explain most variability in why some people stay lean despite identical eating.
A 35-year-old engineer cuts to test his real TDEE
Calculator says TDEE = 2,500 cal/day at "moderately active" (3-5 days lifting). He eats exactly 2,500 cal/day for 3 weeks, tracking carefully. Weekly weight averages:
| Week | Average Weight | Trend |
|---|---|---|
| 1 | 82.4 kg | — |
| 2 | 82.1 kg | −0.3 kg |
| 3 | 81.9 kg | −0.2 kg |
Losing ~0.25 kg/week at "maintenance" means he's actually in a ~250 cal/day deficit. Real TDEE ≈ 2,750, not 2,500. Most likely cause: he overcounted some exercise or NEAT in choosing the multiplier. The lesson — the calculator gives you a starting point, the scale tells you the real answer.
The Activity Multiplier — Where People Get It Wrong
The single biggest source of TDEE estimation error: choosing too high an activity tier. "Moderately active" requires real 30-45min hard exercise 3-5 days/week, not just walking to the train. Honest categorization:
- Sedentary (×1.2) — Desk job, drives to work, no real exercise. ~70% of office workers fall here.
- Lightly active (×1.375) — Job with some walking, OR 1-3 days/week light exercise (yoga, walks).
- Moderately active (×1.55) — Actually hits 30-45 min hard cardio or strength training 3-5 days/week.
- Very active (×1.725) — Trains 6-7 days, or has a physically demanding job (construction, nursing on feet).
- Extreme (×1.9) — Twice-a-day training, marathon prep, or very physical labor (logging, infantry).
How to Test Your TDEE Estimate
The estimate gets you within ±300 calories. The scale gives you the exact answer:
- Eat at your estimated TDEE for 2-3 weeks. Weigh daily, average weekly.
- Holding steady: you nailed it.
- Losing: real TDEE is higher than estimated. Add 200 cal/day, retest.
- Gaining: real TDEE is lower. Subtract 200 cal/day, retest.
This testing approach is far more accurate than any formula. After one or two iterations you'll know your TDEE to within 100 calories.
Why TDEE Changes With Weight Loss
As you lose weight, TDEE drops because:
- BMR scales with body mass. Less tissue = less metabolic demand at rest.
- NEAT decreases unconsciously. Hormonal shifts during a cut reduce spontaneous activity.
- Adaptive thermogenesis adds 5-15% extra slowdown on top of expected BMR drop, especially in aggressive or extended diets.
Recalculate TDEE every 5-10 kg of weight change. This is the reason for diet plateaus — the calorie target that was a deficit at 100 kg is maintenance at 90 kg.
Frequently Asked Questions
How accurate is the activity multiplier?
±300 calories is typical. Biggest error source: overestimating activity. "Moderately active" requires real 30-45min hard sessions 3-5×/week, not just being on your feet at work.
Does TDEE change with weight loss?
Yes — TDEE drops as you lose weight. Recalculate every 5-10 kg of weight change. This is why diets plateau.
What's the most muscle-friendly cut rate?
A 20-25% caloric deficit, combined with adequate protein (~2 g/kg body weight) and resistance training, preserves muscle best. Aggressive cuts (>30% deficit) lose more muscle.
Why does my fitness tracker show a different number?
Wearables estimate calorie burn using heart rate and movement data. They're typically off by 15-25% in either direction. Use them for relative comparisons over time, not absolute numbers.