Guides and articles based on scientific evidence on hypertrophy, strength training, fat loss and muscle recovery. Real expert-written content, no myths.
Body recomposition calculator: lose fat and build muscle
Body recomposition means losing fat and building muscle at the same time. Calculate the calories and protein you need and find out whether your situation is right for trying it.
Can you lose fat and build muscle at the same time?
Yes, and there are studies that show it. In the trial by Longland and colleagues (2016), young men in a marked calorie deficit who trained hard six days a week gained lean mass and lost fat, but only the group eating 2.4 g of protein per kilo did so; at 1.2 g/kg, lean mass did not increase. High protein and strength training are the two conditions that make it possible, and this body recomposition calculator is built around both.
How this calculator works
It starts from your maintenance (Mifflin-St Jeor adjusted for your activity) and applies a slight 10% deficit: enough to lose fat, but not so much that you run short of energy to train and build muscle. It also gives you a macro breakdown with protein at the high end of the range.
Recomposition compared with cutting and bulking
Strategy
Calories
Protein
Best for
Recomposition
Maintenance or −10%
1.8-2.4 g/kg
Beginners, people returning to training, moderate body fat
Cutting
−10 to −25%
1.8-2.4 g/kg
A lot of fat to lose
Bulking
+5 to +15%
1.6-2.2 g/kg
Lean or advanced people who want more muscle
Who it works best for
Beginners: in the first year, muscle responds so well that it can grow even in a slight deficit.
People returning after a break: muscle memory makes regaining what you lost fast.
People with moderate or high body fat: there are plenty of energy reserves.
If you are already lean and have been training for years, recomposition is very slow: alternating surplus and deficit phases usually works better. We compare them in bulking or cutting: where to start.
How to tell if it is working
During recomposition the scale can be misleading: your weight may not move while your body changes. Measure your waist, take photos in the same lighting and log your lifts at the gym. If your waist goes down and your strength goes up, you are on track. For your exact protein target, use the protein calculator.
Frequently asked questions
What is body recomposition?
Losing fat and building muscle at the same time, usually by eating close to maintenance or in a slight deficit, with high protein and strength training.
How many calories should I eat for body recomposition?
Between your maintenance and 10% below it. This calculator uses a 10% deficit, enough to lose fat without leaving you short of energy to train.
How much protein do I need for recomposition?
At the high end of the range, around 1.8-2.4 g per kilo of body weight. In the trial by Longland and colleagues (2016), only the group eating 2.4 g/kg gained lean mass in a deficit.
Calories and protein supply the fuel; training decides what you do with it. Generate a free routine tailored to your goal, your level and your equipment.
Longland TM, Oikawa SY, Mitchell CJ, Devries MC, Phillips SM. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial. American Journal of Clinical Nutrition. 2016;103(3):738-746.
Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition. 2014;11:20.
Jäger R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, et al. International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition. 2017;14:20.
Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition. 1990;51(2):241-247.
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Personal data
Basic info to calibrate your routine precisely
years
kg
cm
Your goal
Define the direction of your training
Optimal rep range
5–15 reps depending on the day · RIR 3–4 → 1–2 · Volume: 12–20 sets/week per muscle group
Planning
Set your weekly availability
4 days → Upper/Lower · higher frequency per group (2×/week)
60 min
Optimizes exercises
The engine adapts the exercise library based on the equipment you have available.
If disabled, the routine, PDF and email will not include the warm-up section.
Preferences
Customise the exercises in your routine (optional)
Exercises you enjoy the most. We will prioritise them in the selection — they will appear more often in your routine if they fit your goal.
✓ Top priority · higher frequency
Exercises
Select the exercises you want to include in your routine
Specific exercises you want out of your routine. We swap them for others working the same muscle group, so you do not lose that work.
✗ Swapped for an alternative
Leave it empty if there is none you want to avoid
Groups you prefer not to train — by preference, accumulated fatigue or any other reason. We will omit them entirely from your routine.
✗ Omitted from the entire routine
Indicate any injured or sensitive area. We will automatically exclude exercises that could aggravate it and apply a safe alternative training protocol.
🛡 Safe protocol activated
Injuries are health data (Art. 9 GDPR). By selecting them you explicitly consent to their processing for the sole purpose of excluding contraindicated exercises. Optional field — you can withdraw consent by removing them. More info in the Privacy Policy.
The groups you want to develop most. They will receive +1 set per exercise, more selected exercises and a priority position in the session.
★ +1 extra set · priority position
Summary
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Generating your routine
Applying scientific principles…
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Profile
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Analysis
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Your personalized routine
Why this routine for you
Auto-generatedThis routine was generated automatically by our own engine from the data you provided. It has not been reviewed by a healthcare professional.
Generated routines are for informational purposes only. They do not constitute medical advice. Consult a professional before starting if you have injuries or health conditions.
Understand my routine
RoutineYour personalized routine
RIRReps in Reserve — how close to failure
RIR tells you how many reps you have left in the tank when you finish a set. RIR 2 means you could do 2 more reps before reaching failure. It's a more precise way to control intensity than using a fixed percentage of your max.
Example: If you do 10 reps of bench press with RIR 2, you could have done 12 at that moment. It's not an exact number — listen to your body.
VolumeTotal sets and reps
Volume is the total work done per muscle group per week (sets × reps × weight). For hypertrophy, 10–20 effective sets per muscle per week is recommended. Your routine adjusts this based on your level and available days. Each set counts in full for the exercise's main muscle and as half for the ones that assist: 4 sets of bench press are 4 for chest and 2 for triceps and shoulders.
Example: 4 sets of bench press + 3 sets of flyes = 7 sets for chest in that session. The weekly total determines how much the muscle grows.
FrequencyDays and weekly structure
Example: With 3 days/week, Full Body is used to train each muscle 3 times. With 4–5 days, muscle groups are split (Push/Pull/Legs or similar).
ProgressionHow to progress week by week
Progression is the most important principle in training. Your body adapts, so you need to give it a greater stimulus each week. The main ways are: adding weight, adding reps, or adding sets.
Tip: When you can hit the top of the rep range (e.g. 12) with good form and RIR 2, add 2.5–5 kg in the next session.
⚠️ You train at your own risk. Suggested loads are guidance only: increase them only if your technique is solid and pain-free. This does not replace advice from a medical professional or trainer. If you feel pain or get injured, stop and consult a specialist.
