Guide · Body recomposition
Macros Calculator: how to set protein, fat, and carbs for body recomposition
A macros calculator turns a calorie target into a daily plan: protein, fat, and carbs. This guide explains which number carries the weight, which ones flex, and how to use the output day by day.
What a macro target actually is
A macro target is three numbers, protein, fat, and carbs, that add up to a calorie target. The macros calculator takes your TDEE and goal, then splits the calorie budget into those three numbers. The calorie total drives the direction of bodyweight. The split decides how much of that change is composition.
Calories are the headline number. Macros decide whether the weight you lose is fat or muscle, and whether the weight you gain is muscle or fat. For body recomposition, the protein number does most of the work. Fat and carbs are the levers you flex around training, hunger, and preference.
Why protein is the load-bearing macro
In a calorie deficit, the body has two ways to cover the gap: burn fat or break down muscle. A high protein intake tells the body to keep the muscle and pull from fat instead. Without that signal, lean mass goes first. That is why recomposition lives or dies on the protein floor.
The research range is 1.6 to 2.2 g per kg of bodyweight, with 2.0 to 2.4 g per kg of lean mass during an aggressive cut. The macros calculator lands you inside that range automatically. Hit the protein number first every day. Fat and carbs fill what is left.
How to use the calculator step by step
- 1. Start from your TDEE.Macros sit on top of a calorie target. If you do not have one yet, run the TDEE calculator first. Maintenance calories are the input the macro split flexes around.
- 2. Pick the goal.Fat loss runs 8 to 22 percent below TDEE. Body recomposition runs 5 to 15 percent below. Muscle gain runs 0 to 15 percent above. The deeper the cut, the more the protein floor matters.
- 3. Lock in protein.1.6 to 2.2 g per kg of bodyweight, or 2.0 to 2.4 g per kg of lean mass if you have a body fat estimate from the body fat calculator. The protein calculator handles the conversion if you want to see the math.
- 4. Set the fat floor.Fat covers hormonal health. The floor is about 0.7 g per kg of bodyweight, or roughly 20 percent of calories. Below that, sleep and recovery start to drag. Above it, the choice is preference.
- 5. Fill the rest with carbs.Whatever calories remain after protein and fat become carbs. Keep at least about 50 g per day so training intensity holds. The carb number is the most flexible of the three.
How the three numbers play together
The calorie target sets direction. Protein protects composition. Fat covers hormones. Carbs fuel training. Those four roles map cleanly onto the three macros, with calories sitting above as the constraint that ties them together.
Protein and the calorie total are the non-negotiables. The fat-versus-carb split is a preference dial. A higher-fat plan suits people who train less or feel better with steady energy. A higher-carb plan suits people who train hard or perform best with fuel around sessions. Both work if calories and protein are right.
The targets shift as bodyweight changes. Drop 5 kg and the protein floor drops with it. Add lean mass and the calorie target rises. Recalculate macros every 4 to 6 weeks, or whenever bodyweight moves more than 3 to 4 kg from the last input.
Common mistakes using a macros calculator
- Chasing the perfect split. 40/30/30, 50/25/25, keto, high-carb. None of these win once protein and calories are locked. Pick a fat-carb split you can hit consistently and stop optimizing the ratio.
- Treating protein as a maximum, not a floor. Going over the protein target is fine. Going under, especially in a deficit, is what costs you lean mass. Hit it first, every day, before counting the rest.
- Skipping the TDEE step. Macros without a calorie anchor are guesses. If you have not estimated maintenance from the TDEE calculator, the macro plan rides on assumed calories. Errors compound across the week.
- Forgetting that the calculator output has error bars. Calorie targets carry a typical 10 percent error from BMR estimation. Run the plan for 7 to 10 days, watch the weight trend, then adjust calories by 100 to 200 kcal a week while holding the protein floor constant.
Once you have your macros, what to do with them
Three numbers and a calorie ceiling are the entire daily plan. Hit protein first. Stay close to the calorie total. Let fat and carbs flex around what the day looks like. The weekly weight trend, not any single day, tells you whether the plan is working.
The Recomp AI macros calculator returns your protein, fat, and carb targets in grams, plus the calorie total they add up to. From there, log a few representative days and the targets become muscle memory. The math is the easy part. The adherence is the work.
Frequently asked questions
How accurate is a macros calculator?
The split math is exact. The calorie target it sits on carries the usual 10 percent error from BMR and activity estimation. Use the calculator output as the starting line, then adjust calories from the weekly weight trend while holding the protein number constant.
Do I really need to hit my macros exactly?
Hit protein within about 5 g. Stay within 100 to 150 kcal of the calorie total. The fat-versus-carb split can swing 20 g either way without breaking the plan. Precision matters most on protein and calories. Everything else is range, not target.
What are the best macros for body recomposition?
A 5 to 15 percent calorie deficit, 1.6 to 2.2 g of protein per kg of bodyweight, fat at or above 0.7 g per kg, and carbs filling the rest. The training has to do real work too. Recomposition is calorie precision and protein discipline paired with consistent resistance work.
How often should I recalculate my macros?
Every 4 to 6 weeks, or whenever bodyweight moves more than 3 to 4 kg from the last input. Adaptation pulls the calorie target down as a cut deepens, and the protein floor scales with bodyweight, so the numbers drift over time.