Body Recomp Calc

Calculators

• Body Recomposition Macro Calculator
  Estimate calories, protein, fat and carbs to lose fat and build muscle at the same time. Metric or imperial.
• Protein Intake Calculator
  Daily protein range for people who strength train, split across your meals.

What the inputs mean

Bodyweight is used in every formula on this site, so enter it accurately. The Mifflin-St Jeor equation and the protein range (1.6–2.2 g/kg) both scale linearly with weight — a 5 kg error shifts your daily calorie target by roughly 35–50 kcal and your protein target by 8–11 g.

Height and age feed the resting energy estimate. Taller people have more lean mass at the same weight, which raises maintenance calories; older people have a modestly lower resting rate. Neither matters much on its own, but both improve the starting-point accuracy enough to be worth entering correctly.

Activity level is the multiplier applied to resting energy to get daily maintenance. Most people overestimate this. Sedentary (desk job, no structured exercise) is 1.2; lightly active (1–3 sessions a week) is 1.375; moderately active (4–5 sessions) is 1.55. If you are unsure, choose one level lower than you think — it is easier to add calories than to wonder why nothing is happening.

Goal shifts the calorie target. Recomposition sets a 10% deficit while holding protein high. Fat loss uses a larger deficit. Maintenance keeps calories at the activity-adjusted estimate. Lean bulk adds a small surplus. The protein target stays at 1.6–2.2 g/kg regardless of goal, because the evidence for that range holds across all four.

Meals per day (protein calculator only) divides your daily protein target into per-meal figures. Spreading protein across three or four meals keeps each serving inside the range that reliably triggers muscle protein synthesis; the absolute daily total matters more, but the per-meal split is a useful practical guide.

How the two calculators fit together

Start with the body recomposition calculator. It sets a daily calorie target from your height, weight, age, sex and activity using the Mifflin-St Jeor equation, then splits that target into protein, fat and carbohydrate. Use it when you want one number to eat to each day.

Use the protein intake calculator when the calorie side is already settled and the question is only how much protein to eat and how to spread it. It returns a daily range and a per-meal figure, which is the part most people get wrong — hitting a daily total but taking most of it in one sitting.

The two agree by design: the protein figure the recomposition calculator produces sits inside the range the protein calculator returns for the same bodyweight.

What body recomposition actually means

Recomposition is losing fat and gaining muscle at the same time, rather than doing each in separate phases. It is slower on the scale than a straight cut, because the two changes partly cancel out in bodyweight while body composition shifts underneath.

It works best for people who are new to structured training, returning after a break, or carrying enough body fat to fuel muscle growth in a small deficit. Trained lifters near their genetic ceiling generally do better alternating dedicated gaining and cutting phases. The calculator says which case you are likely in based on the inputs you give it.

Because the scale moves slowly, judge progress on a three to four week view using waist measurements, how lifts are progressing and how clothes fit — not on daily weigh-ins.

Protein: the number that does the work

Protein is the input with the strongest evidence behind it. The ISSN position stand on protein and exercise places the useful range at roughly 1.6–2.2 g per kg of bodyweight per day for people who train, with about 0.25 g per kg per meal as a sensible serving to trigger muscle protein synthesis.

For an 80 kg lifter that is about 128–176 g a day, and roughly 20 g in each meal as a floor. Spreading intake across three or four meals is easier to hit than two large ones, and makes the per-meal threshold straightforward.

Food values in the examples come from USDA FoodData Central, so a figure on this site can be traced to a public database rather than a rounded number from a blog.

How to use the results

Treat the output as a starting point and let two to three weeks of real data correct it. If weight and waist are both flat and lifts are progressing, the target is working. If nothing moves in either direction after three weeks, adjust calories by a small amount rather than overhauling the plan.

Weigh yourself under the same conditions each time, ideally several mornings a week, and compare weekly averages rather than single readings. Day-to-day swings from water, sodium and food volume are larger than the change you are trying to detect.

Neither calculator is medical or dietary advice, and neither accounts for medical conditions, medication or pregnancy. If any of those apply, or something here conflicts with advice you have been given, follow the advice.

What you can work out here

Every calculator here works from your own inputs — weight, calories, timeline — so the result fits you, not an average.

Body Recomposition Macro Calculator

This body recomp calculator sets daily calories about 10% below your estimated maintenance and holds protein at 1.6–2.2 g per kg of body weight, which is the setup most people use to lose fat and gain muscle at the same time.

Protein Intake Calculator

This protein intake calculator returns 1.6–2.2 g of protein per kg of body weight per day, then divides that range by the number of meals you eat. At 80 kg that is 128–176 g a day, or 32–44 g across four meals.

Common questions