Body recomposition
TDEE Calculator for Body Recomposition
Estimate your Total Daily Energy Expenditure from weight, height, age, sex, and activity level. Use it as the maintenance calorie anchor for fat loss, body recomposition, or lean muscle gain, then tune the target weekly from a 7-day weight trend.
What is TDEE (Total Daily Energy Expenditure)?
Bodyweight follows one equation: change in weight equals calories in minus calories out. Calories in is straightforward, you eat them. Calories out is what people loosely call metabolism, and it has three components working at once: your basal metabolic rate (BMR), your physical activity level, and the thermic effect of food (TEF). Together they make up Total Daily Energy Expenditure, your daily calorie burn.
For body recomposition, TDEE is the anchor every other number reads off. A cut is TDEE minus 15 to 25 percent. A recomposition setting is TDEE minus 5 to 15 percent. A lean bulk is TDEE plus 5 to 15 percent. Without an estimate of TDEE you cannot define what any of those targets mean in calories.
TDEE calculator with body fat
The body-fat step is optional. Leave it blank and the calculator estimates resting energy from height, weight, age, and sex. Enter a body-fat percentage and it switches to your lean body mass instead, which is the tissue that drives most of your daily burn. Two people at the same weight but different body composition do not burn the same calories, and a lean-mass estimate captures that gap.
If you already measured body fat in the body fat or lean body mass calculator, the figure carries over and pre-fills this step automatically. The result then labels a TDEE with body fat value alongside the lean-mass resting burn, so you can anchor a recomposition target on the sharper number.
TDEE is the floor every recomposition protocol stands on
Body recomposition is fat loss and muscle gain at the same time. It happens in a narrow window around maintenance: a small deficit for most people, maintenance for advanced lifters who are already lean, even a slight surplus for lean beginners with a real training stimulus. Every one of those targets is anchored to TDEE.
The recomposition window, by % of TDEE
Cut deeper than 20 percent and lean mass starts to leave with the fat. Push past a 5 to 10 percent surplus and most of the gain is fat. The green band is where the body has just enough fuel to build muscle and just enough deficit (or training overload) to drop fat at the same time.
NEAT is the lever you have most leverage over. Daily walks, the stairs, a standing desk, parking far from the door. Two people with the same height, weight, and gym schedule can differ by 500 to 800 kcal a day on NEAT alone. It is why a friend can eat 1,000 calories more than you and stay just as lean.
Aggressive deficits punish you twice. When the cut runs too deep or too long, the body senses the fuel shortage and quietly downregulates NEAT. You fidget less, walk less, slump more. This is adaptive thermogenesis, the slowed metabolism chronic dieters describe. A moderate 10 percent deficit, high protein, real training, and a weekly trend check protects metabolism and lean mass while still moving fat off.
The calculator is a starting line, not a finish line. Mifflin has a typical error of about 200 kcal per day. Eat at it for 7 to 10 days, watch the weight trend, and adjust by 100 to 200 kcal a week until the trend matches the goal. That iterative loop is the actual recomposition workflow.
Recompose with Recomp AI
From a TDEE estimate to a recomposition target that updates every week.
Recomp AI logs intake in a 30-second daily chat, watches the weight trend, and nudges your calorie target by 100 to 200 kcal when the trend drifts. The TDEE you see today becomes a moving baseline that follows your real metabolism.
TDEE and body recomposition, explained
The questions people search when the calorie target on paper does not match what the scale is doing.