TDEE calculator

TDEE: your real maintenance calories

Total daily energy expenditure (TDEE) is the actual number of calories you burn in a 24-hour period, combining your resting metabolic rate with the energy cost of all activity — exercise, walking, fidgeting, digesting food, everything. It's the most important number for any body composition goal: eat at TDEE and weight stays stable; eat below it and fat comes off; eat above it and you grow.

Why the activity multipliers are intentionally conservative

The activity multipliers in TDEE formulas (1.2–1.9) look simple, but they hide a significant problem: most people overestimate their activity level, and the formulas were calibrated for people who accurately report theirs. Research consistently shows that individuals claiming "moderate exercise 3–5 days/week" often mean sporadic 30-minute walks, not 45-minute progressive strength sessions. If you have any doubt, go one level lower than your instinct.

NEAT: the hidden variable in your calorie burn

Non-exercise activity thermogenesis (NEAT) is the energy you burn through all movement that isn't formal exercise: fidgeting, walking between rooms, standing vs. sitting, doing chores, gesturing while talking. NEAT varies by 300–800 calories per day between individuals with the same body size and exercise habits. A naturally fidgety office worker may burn 600 more calories per day than a calm, sedentary counterpart — without ever stepping in a gym.

NEAT also suppresses during caloric restriction. When calories drop, the body unconsciously reduces NEAT — you sit more, move less between tasks, fidget less. This NEAT suppression can reduce actual TDEE by 100–300 calories per day below the calculated estimate, which is one reason why weight loss often slows faster than expected.

Thermic effect of food (~10% of TDEE)

Digesting and metabolizing food burns calories — roughly 10% of total TDEE for most mixed diets. Protein has the highest thermic effect (25–30% of its calories are burned in digestion), compared to carbohydrates (6–8%) and fat (2–3%). A high-protein diet isn't just satiating — it modestly increases total daily calorie burn through this thermogenic effect.

Adaptive thermogenesis: the plateau mechanism

Prolonged caloric deficits trigger adaptive thermogenesis — a metabolic slowdown beyond what can be explained by fat and muscle loss alone. Studies suggest that after significant weight loss (10%+ of body weight), resting metabolic rate decreases by an additional 100–300 calories per day above and beyond the reduction expected from smaller body mass. This is the biological mechanism behind weight loss plateaus and why crash diets often lead to rapid weight regain. Diet breaks (returning to maintenance for 1–2 weeks) can partially restore metabolic rate.

How to use TDEE in practice

The most reliable method is empirical calibration:

1. Start at your calculated TDEE. Log everything for 2 full weeks as accurately as possible.
2. Weigh yourself every morning under the same conditions (post-bathroom, pre-food). Calculate the average weight for week 1 and week 2.
3. Compare the weight trend to your logged calories. If you ate an average of 2,300 calories and gained 0.5 lb over 2 weeks, your true maintenance is roughly 2,300 − (0.5 × 3,500 / 14) ≈ 2,175 calories/day.
4. Adjust accordingly. This real-world calibration beats any formula.