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Body Recomp Calc Free calculator
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. Enter age, sex, height, weight and activity to get calories plus protein, fat and carbs in grams.
Updated
General estimate only, not medical or dietary advice. Not suitable for anyone under 18, pregnant, or managing a medical condition or eating disorder.
- Updated September 2026
- Free — no sign-up
- Sources cited
Who recomposition works best for
Recomposition means losing fat and adding muscle at roughly the same time, instead of doing them in separate phases. It asks a lot of your body, so it tends to suit some people more than others.
| Situation | Why it helps or hurts |
|---|---|
| New to resistance training | Untrained muscle responds strongly to a first training block, so gains can happen even without a calorie surplus. |
| Returning after a long break | Rebuilding previously trained muscle is usually faster than building it the first time. |
| Higher body fat to start | More stored energy to draw on, so a small deficit is easier to sustain alongside hard training. |
| Currently under-eating protein | Simply moving into the 1.6–2.2 g/kg range changes a lot on its own. |
| Lean and well trained | Hardest case. Progress is slow enough that separate cutting and lean bulking phases are usually more efficient. |
Nothing here is guaranteed, and rates vary widely between people. Sleep, training consistency, stress and how accurately you track food all move the result more than the exact calorie number does.
If you mainly want to lose fat quickly, choose the cut goal (−20%) instead. If you are already lean and want size, choose lean bulk (+10%). Recomp is the middle option, not the best option for everyone.
How the calculator works (Mifflin-St Jeor)
The calculator runs four steps, in this order.
1. Resting energy. It uses the Mifflin-St Jeor equation from Mifflin, St Jeor et al., American Journal of Clinical Nutrition 1990;51(2):241–247:
| Sex | Resting energy (kcal/day) |
|---|---|
| Male | 10 × kg + 6.25 × cm − 5 × age + 5 |
| Female | 10 × kg + 6.25 × cm − 5 × age − 161 |
Pounds are converted at 0.45359237 kg per lb and feet and inches at 2.54 cm per inch, so metric and imperial give the same answer.
2. Maintenance. Resting energy is multiplied by the activity factor you pick: 1.2 (mostly sitting), 1.375 (light, 1–3 days a week), 1.55 (moderate, 3–5 days), 1.725 (hard, 6–7 days) or 1.9 (very hard training or a physical job).
3. Goal adjustment. Maintain applies 0%, body recomposition −10%, fat loss −20% and lean bulk +10%. These percentages are starting-point conventions, not clinical figures.
4. Macros. Protein is your body weight in kg times the g/kg figure you select (1.6, 1.8, 2.0 or 2.2, default 2.0). Fat is the fat share of calories you set, 25% by default, divided by 9 kcal per gram. Carbs take whatever calories are left, at 4 kcal per gram. If protein and fat alone exceed the calorie target, the tool warns you to lower the fat share.
Adjusting after 2–3 weeks
Every step above is an estimate. The activity multiplier in particular is a rough bucket, so treat the output as a starting number and let your own data correct it after two to three weeks.
Two to three weeks is long enough for day-to-day water and food weight to average out. Weigh yourself under the same conditions most mornings and compare weekly averages rather than single readings. Add one or two tape measurements (waist at the navel, and one you care about, such as upper arm or thigh) because recomposition can hold scale weight flat while measurements move.
| What the three weeks showed | A reasonable next move |
|---|---|
| Weight flat, waist down, lifts up | Recomposition is happening. Change nothing. |
| Weight and measurements both flat, lifts flat | Lower calories by roughly 5% to 10%, or add activity. |
| Losing faster than about 1% of body weight a week | Add calories back, mostly as carbs. Fast loss costs muscle. |
| Weight rising and waist rising | You are above maintenance. Recheck your logging, then lower calories. |
| Hungry, sleeping badly, training worse | Move toward maintenance for a while. A deficit you cannot keep is not useful. |
Recalculate whenever your weight changes by a few kilograms, since protein and calorie targets both scale with body weight.
Training alongside
The macros only matter if there is a training stimulus to spend them on. In a slight deficit, resistance training is the signal that tells your body to keep and build muscle rather than lose it.
The ISSN position stand on protein and exercise (Jäger et al., 2017) frames its protein recommendations around exercising individuals doing resistance training, and Morton et al., British Journal of Sports Medicine 2018 analysed protein alongside prolonged resistance training programmes. Neither looked at protein on its own.
A workable structure while recomping:
- Lift two to four times a week, covering the whole body across the week.
- Keep the main lifts and try to add reps or load over time. Progress on the bar is the clearest sign you are holding muscle.
- Take most working sets close to, but not to, failure, and keep total weekly sets per muscle group steady rather than chasing volume.
- Add easy cardio or step targets for the calorie side instead of making the lifting sessions harder.
- Protect sleep. Recovery capacity is lower in a deficit, so cut training volume before you cut sleep.
If your lifts are falling week after week, that is the cue to eat more, not train more. Pair this page with the protein intake calculator if you want the daily protein figure split across meals.
Frequently asked questions
How do I calculate my body recomp?
Estimate maintenance calories, subtract about 10%, then set protein at 1.6–2.2 g per kg of body weight and fat at roughly 25% of calories, leaving carbs as the remainder. This calculator does exactly that, using the Mifflin-St Jeor resting energy equation and an activity multiplier from 1.2 to 1.9. Treat the result as a starting point and adjust it from your own weight and measurement trend.
How long does body recomposition typically take?
There is no reliable published timeline, and anyone quoting one is guessing. What you can measure is your own trend: compare weekly average weight, waist measurement and lift performance over two to three week blocks. Visible change usually takes months rather than weeks, and it is slower the leaner and more trained you already are. Judge progress by the measurements, not by a calendar.
Can I recomp at 25% body fat?
Yes, and higher body fat is generally the easier starting point, because there is more stored energy available to support training while you eat slightly below maintenance. Use the recomp goal (−10%) with protein at the upper end of the range. If fat loss is your clear priority at that level, the cut goal (−20%) will move the scale faster, and you can switch back later.
Is 3 months enough for body recomp?
Three months is enough to see a measurable trend, not necessarily enough to finish. Expect changes you can read on a tape measure and in your lifts before changes you can see in a mirror. Keep the same calorie and protein targets for at least two to three weeks at a time, recalculate when your weight shifts by a few kilograms, and judge the block on averages rather than any single day.
Sources
- Mifflin, St Jeor et al., American Journal of Clinical Nutrition 1990;51(2):241–247 (resting energy equation used here)
- Morton et al., British Journal of Sports Medicine 2018 (protein plateau 1.62 g/kg/day, 95% CI 1.03–2.20)
- ISSN position stand on protein and exercise (Jäger et al., 2017)
Related
General estimate only, not medical or dietary advice. Not suitable for anyone under 18, pregnant, or managing a medical condition or eating disorder.