TDEE is the foundation of any calorie target, but the right adjustment depends entirely on your goal. This page is the TDEE calculator dialed in for body recomposition: get your maintenance number from Mifflin-St Jeor, then read a section written specifically for this goal — including the deficit or surplus size that the evidence actually supports, not the aggressive numbers most calculators default to.
Your TDEE is the calorie level at which weight stays flat. Every plan aimed at body recomposition is a deliberate distance from that line: a deficit for fat loss, a surplus for muscle gain, near-zero for maintenance or recomposition. Get TDEE wrong by 300 kcal and your plan is mathematically a different plan.
The calculator below gives you the Mifflin-St Jeor estimate. Treat it as a starting point — for body recomposition, the practical TDEE that drives results is the one you confirm against 2–3 weeks of weight-trend data.
Aggressive deficits and bulks both backfire. For fat loss the evidence supports 0.5–1.0% bodyweight loss per week, which in calorie terms is roughly 300–500 kcal below TDEE for most people — slower if lean mass preservation matters more than speed. For lean bulks, 0.25–0.5% gain per week (200–400 kcal surplus) keeps the fat:muscle ratio in your favour.
Maintenance is exactly that — eat at TDEE and let training drive composition change. Recomposition sits within ±100 kcal of TDEE combined with high-protein intake and progressive resistance training; it is the slowest visible change but the most sustainable for body recomposition.
Three failure modes show up repeatedly for body recomposition: starting with a too-aggressive number (chosen by ego, not biology), failing to recalibrate as TDEE drifts down with weight loss or up with lean-mass gain, and confusing daily noise (water, sodium, glycogen, cycle phase) with the weekly trend that actually matters.
Pick a target that you can hold for 8–12 weeks without misery. A 350-kcal deficit you maintain for three months always beats a 700-kcal deficit you blow up in six weeks.
Inside AJYX, your calorie target is not a fixed number from a one-time calculation. The app recalibrates TDEE weekly from your real weight trend versus your real intake, and shifts the deficit or surplus to keep the rate of change in the right zone for body recomposition.
If you stall, AJYX adjusts — not by adding willpower demands, but by trimming or expanding the target by 100–150 kcal. That is the difference between a plan that works on paper and one that works in your life.
For fat-loss goals, 300–500 kcal below TDEE supports 0.5–1.0% bodyweight loss per week, which preserves the most lean mass. Larger deficits accelerate weight loss but cost more muscle and adherence. Start at the smaller end and only push lower if the rate is too slow.
For muscle-gain or lean-bulk goals, 200–400 kcal above TDEE supports 0.25–0.5% bodyweight gain per week. Slower is better — beyond ~500 kcal surplus the extra weight is mostly fat, not muscle, in trained lifters.
Every 4–6 weeks of meaningful weight change, or whenever the weekly trend stops matching the plan. As you lose weight your TDEE drops by roughly 25–30 kcal per kilogram lost; as you add lean mass it rises slightly.
Yes, especially if you are a beginner, returning after a layoff, or have meaningful fat to lose. Recomposition needs high protein (1.6–2.2 g/kg), progressive resistance training and patience — visible change takes 8–16 weeks.
For deficits longer than 8–10 weeks, planned diet breaks (1–2 weeks at TDEE) help restore performance, hormones and adherence without losing fat-loss progress. Refeed days within a week are optional and matter most for very lean trainees.