TDEE calculator that corrects for your diet history
Mifflin-St Jeor, then an adaptation correction of up to fifteen per cent for adults who have been through repeated deficits. Most calculators skip that step. It is the reason their number never worked for you.
6
Questions
0–15%
Correction applied
2 wk
To verify it
Six questions, one honest number
TDEE + Adaptation
Question 1 of 6
What comes out
- Maintenance calories, corrected
- A fat-loss target at a 17.5% deficit
- Protein at 1.6 g/kg bodyweight
- Fat at 30% of calories, carbs as the remainder
Metric in, metric out. 1 lb ≈ 0.45 kg · 1 ft ≈ 30.5 cm.
Pick the lower rung
Activity level is where nearly everyone overestimates. Three gym sessions a week on top of a desk job is “light”, not “moderate”. If your number comes out higher than what you already eat without gaining, drop a rung and run it again.
What dieting history costs you, in calories
Tap through the four histories to see the correction applied to a neutral 2,400 kcal example. The percentages are the ones the calculator uses on your own numbers.
Tap a dieting history
Worked example · 2,400 kcal uncorrected
168 kcal/day lower than the standard equation predicts — a 7% reduction.
3–5 prior diets
A moderate correction. Müller and Bosy-Westphal quantify adaptive thermogenesis more conservatively than the headline figures, but agree on the direction — expenditure falls further than mass change alone predicts.
The correction is a calibrated heuristic drawn from the adaptive-thermogenesis literature, not a measurement of your metabolism. Indirect calorimetry is the only way to measure it directly.
Adaptive thermogenesis is a defence, not a defect
Rosenbaum and Leibel characterised the response as a five to fifteen per cent drop in expenditure beyond what mass change alone explains. Müller and Bosy-Westphal put the figure more conservatively. They disagree on magnitude and agree on direction.
Leptin falls, and stays down
Losing fat lowers leptin, which the hypothalamus reads as a shortage. Sympathetic output and thyroid conversion both ease off in response.
Muscle gets more efficient
Post-diet skeletal muscle does the same mechanical work for fewer calories. That efficiency is a survival feature, not a malfunction.
Spontaneous movement drops
Fidgeting, pacing, gesturing — non-exercise activity quietly falls in a deficit, and nobody notices themselves doing less of it.
It persists after the diet ends
Fothergill measured resting metabolic rate around 500 kcal/day below prediction six years on, in people who had largely regained the weight.
None of this means fat loss stops being possible. It means the plan for a six-time dieter has to look different from the plan for a first-timer: more protein, resistance training treated as non-negotiable, and a shallower deficit held for longer.
Two weeks beats any equation
Eat to the number for two weeks
Same intake every day, weighed rather than estimated. Two weeks is the shortest window that survives water-weight noise.
Weigh under identical conditions
Morning, after the bathroom, before food. Take the seven-day average, never a single day’s reading.
Read the trend, not the day
Flat average across two weeks means you have found maintenance. A falling average means the target is working as a deficit.
Adjust in small steps
Move by 100–150 kcal, then wait another fortnight. Larger corrections just re-introduce the noise you were trying to remove.
Protein first, always
The macro split the calculator returns starts at 1.6 g/kg protein for a reason — it is the range where the meta-analytic evidence supports lean-mass retention during an energy deficit.
What we will not tell you
How much you will lose, or by when. Nobody can honestly predict that for an individual. What we can say is that the intake you can actually hold beats the one that looks best on paper. Individual results vary.
Straight answers
What people ask about TDEE
Total daily energy expenditure is everything you burn in twenty-four hours: your resting metabolic rate, the cost of digesting food, deliberate exercise, and all the incidental movement in between. It is the intake at which your weight should hold steady.
We calculate resting rate with the Mifflin-St Jeor equation, multiply by an activity factor, then apply a correction for your dieting history. The output is a starting hypothesis to test — not a fixed property of your body.
Estimates only. Energy needs vary between individuals with the same measurements.
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A calorie target is not a plan
The assessment reads this number against your sleep, training, dietary pattern and weight history — then routes you to the protocol the evidence supports for that profile.
References
- 01Fothergill E et al. (2016). Persistent metabolic adaptation 6 years after 'The Biggest Loser' competition. Obesity. PubMed 27136388
- 02Rosenbaum M, Leibel RL (2010). Adaptive thermogenesis in humans. International Journal of Obesity. PubMed 20840326
- 03Müller MJ, Bosy-Westphal A (2013). Adaptive thermogenesis with weight loss in humans. Obesity. PubMed 23404931
- 04Trexler ET, Smith-Ryan AE, Norton LE (2014). Metabolic adaptation to weight loss: implications for the athlete. Journal of the International Society of Sports Nutrition. PubMed 24571926
- 05Hall KD et al. (2011). Quantification of the effect of energy imbalance on bodyweight. The Lancet. PubMed 21872751
- 06Pontzer H et al. (2016). Constrained total energy expenditure and metabolic adaptation to physical activity in adult humans. Current Biology. PubMed 26832439
- 07Westcott WL (2012). Resistance training is medicine: effects of strength training on health. Current Sports Medicine Reports. PubMed 22777332
Educational only, not medical advice. TDEE is an estimate, not a measurement, and individual energy needs vary widely at identical body measurements. Consult your physician before major dietary changes or altering prescribed medication. These statements have not been evaluated by the Food and Drug Administration. Individual results vary; no outcome is guaranteed.