Free Tool
Adaptive Calorie Calculator
Free here • Paid in MacroFactor, Carbon, Stronger U
Predictive TDEE equations have a ±300 kcal error per person. The only way to know your real maintenance is to measure energy in versus weight change out. Enter 7 days of data and we will tell you what you actually burn.
New to TDEE? Read the plain-English definition →
Last 7 days
Your numbers
Actual weekly change
-0.9 lb
-451 kcal/day balance
True maintenance
2851 kcal
You assumed 2900 kcal
New daily target
2352 kcal
To hit -1 lb per week
Your previous TDEE estimate was within 50 kcal of reality. The new target reflects normal weekly fluctuation.
Get this recalculation every Sunday in Zealova, automatic
We pull your week of food log entries and weigh-ins, run the math, and push the updated calorie target into your plan.
Free 7-day trial. $7.99/mo or $59.99/yr after. Cancel anytime.
Methodology + Sources
- Hall KD (2007). Body fat and fat-free mass inter-relationships: Forbes's theory revisited. NEJM 357:1611.
- Hall KD (2008). What is the required energy deficit per unit weight loss? Int J Obes 32(3):573-6.
- Trexler ET, Smith-Ryan AE, Norton LE (2014). Metabolic adaptation to weight loss: implications for the athlete. JISSN 11:7.
- Frankenfield D et al. (2005). Comparison of predictive equations for resting metabolic rate. J Am Diet Assoc 105(5):775-89.
Last updated: 2026-05-14
Built by Sai, founder of Zealova. Not a neutral third party. Calculator results are estimates. For medical decisions, consult a qualified professional.
Frequently asked questions
Why does my TDEE keep changing?+
NEAT (non-exercise activity) is the largest variable in daily energy expenditure, and it adapts. As you lose weight your body moves less, fidgets less, and burns slightly less per step. BMR also drops in proportion to lost mass. A TDEE that was correct in week 1 is often 100 to 200 kcal too high by week 6.
What is metabolic adaptation?+
Beyond the predictable drops in BMR and NEAT, prolonged dieting triggers further adaptive thermogenesis: thyroid hormones decline, sympathetic tone drops, and leptin falls. This adds another 5 to 15% reduction in daily energy expenditure beyond what BMR equations predict. It is reversible with diet breaks and refeeds.
How accurate is this with 7 days of data?+
Accurate enough to outperform any predictive equation. A 7-day rolling window filters most water-weight noise. For best results weigh in at the same time of day, in the same conditions, for the full 7 days. Track every calorie honestly. The math is only as good as your inputs.
What if my weight went the wrong direction?+
That is exactly what this calculator was built for. If you gained weight while in what should have been a deficit, your assumed TDEE was wrong. The new target accounts for the real number and gets you back on trajectory.
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