Body Recomposition Calculator
Use this body recomposition calculator to find calorie and protein targets for losing fat while building muscle.
Updated August 8, 2026
Calculated instantly in your browser — nothing is sent to or stored on our servers.
Medical Disclaimer: This calculator provides a general estimate based on established research and is for educational purposes only, not a substitute for medical advice. Individual results can vary based on health conditions, so consult a qualified healthcare professional or registered dietitian before making significant changes to your diet, exercise, or health routine. Read our full Medical Disclaimer.
How Body Recomposition Is Calculated
Most goal-based calculators on this site pick a lane: a deficit for fat loss, a surplus for muscle gain. Body recomposition asks for both at once, which is a genuinely harder target, and no single validated formula exists for it. This calculator instead builds around the two levers the evidence actually supports.
What This Calculator Measures
This gives you a calorie target and a protein target designed to support simultaneous fat loss and muscle retention or growth. It does not replace a training program, resistance training is what makes recomposition possible in the first place.
Step 1: Determine Your TDEE
You can either enter your daily calorie target directly, or let us estimate it from your stats using the same Mifflin-St Jeor and activity-multiplier method used by our TDEE Calculator.
Step 2: Apply a Small Deficit
Rather than a large deficit, we apply a smaller one, roughly 10 to 20% below your TDEE. Aggressive deficits work against simultaneous muscle building, so recomposition trades speed for a better shot at holding onto, or gaining, muscle while losing fat.
Calorie target = TDEE × (0.80 to 0.90)
Step 3: Set a Protein Target
We set protein at 1.6 to 2.2 g per kg of bodyweight per day, roughly 0.7 to 1 g per lb, the range with the strongest support for preserving or building muscle in a calorie deficit¹, a finding also demonstrated directly in a randomized trial of resistance-trained men in a marked energy deficit². We also break this into a rough per-meal count, since one large daily number is harder to act on mid-day.
Protein target (g/day) = Weight (kg) × 1.6 to 2.2
How This Calculator Computes Your Result
Enter your stats and training status above, using either path from Step 1. We apply the deficit and protein formulas, then adjust the messaging in your result based on your training status, since recomposition is more realistic for some starting points than others.
Step 4: Factor In Body Fat and Training Status
Recomposition is most realistic for beginners, returning trainees, or people with higher body fat percentages, they can often lose fat and build muscle at the same time. It’s still possible for lean, already-trained individuals, but progress is typically much slower, which we reflect in your result based on your training status.
A Note on Accuracy
Body recomposition is the slowest of the goal-based approaches, set pace expectations honestly. Resistance training is a stated prerequisite, the calorie and protein numbers alone don't build or preserve muscle without a training stimulus. No single validated recomposition formula exists, so this builds around the two levers with the strongest evidence: a modest deficit and adequate protein.
Frequently Asked Questions
Why is the deficit smaller than other weight-loss calculators?
A large calorie deficit works against building or maintaining muscle. Recomposition uses a smaller deficit, about 10 to 20% below TDEE, so you're losing fat slowly enough that your body can still support muscle growth or preservation with adequate protein and training.
Why is my protein target a range instead of one number?
Protein needs for preserving or building muscle in a deficit fall in a range, 1.6 to 2.2 g/kg bodyweight per day, depending on training experience, body fat level, and individual factors¹. We show a range and a per-meal breakdown rather than pretending to more precision than the evidence supports.
Is body recomposition realistic for everyone?
It's most realistic for beginners, returning trainees, or people with higher body fat percentages, since they can often lose fat and gain muscle at the same time. It's still possible for lean, already-trained individuals, but progress is typically much slower, this calculator reflects that through your training-status input.
Do I still need to lift weights for this to work?
Yes. Resistance training is a prerequisite, not optional. The calorie and protein targets create the right conditions, but a training stimulus is what actually signals your body to build or preserve muscle.
Sources
Evidence-Based Recommendations for Natural Bodybuilding Contest Preparation: Nutrition and Supplementation, Helms, Aragon & Fitschen, 2014
Higher Compared With Lower Dietary Protein During an Energy Deficit Combined With Intense Exercise Promotes Greater Lean Mass Gain and Fat Mass Loss, Longland et al., 2016
Body Recomposition Calculator
Use this body recomposition calculator to find calorie and protein targets for losing fat while building muscle.
Updated August 8, 2026
Calculated instantly in your browser — nothing is sent to or stored on our servers.
Medical Disclaimer: This calculator provides a general estimate based on established research and is for educational purposes only, not a substitute for medical advice. Individual results can vary based on health conditions, so consult a qualified healthcare professional or registered dietitian before making significant changes to your diet, exercise, or health routine. Read our full Medical Disclaimer.
How Body Recomposition Is Calculated
Most goal-based calculators on this site pick a lane: a deficit for fat loss, a surplus for muscle gain. Body recomposition asks for both at once, which is a genuinely harder target, and no single validated formula exists for it. This calculator instead builds around the two levers the evidence actually supports.
What This Calculator Measures
This gives you a calorie target and a protein target designed to support simultaneous fat loss and muscle retention or growth. It does not replace a training program, resistance training is what makes recomposition possible in the first place.
Step 1: Determine Your TDEE
You can either enter your daily calorie target directly, or let us estimate it from your stats using the same Mifflin-St Jeor and activity-multiplier method used by our TDEE Calculator.
Step 2: Apply a Small Deficit
Rather than a large deficit, we apply a smaller one, roughly 10 to 20% below your TDEE. Aggressive deficits work against simultaneous muscle building, so recomposition trades speed for a better shot at holding onto, or gaining, muscle while losing fat.
Calorie target = TDEE × (0.80 to 0.90)
Step 3: Set a Protein Target
We set protein at 1.6 to 2.2 g per kg of bodyweight per day, roughly 0.7 to 1 g per lb, the range with the strongest support for preserving or building muscle in a calorie deficit¹, a finding also demonstrated directly in a randomized trial of resistance-trained men in a marked energy deficit². We also break this into a rough per-meal count, since one large daily number is harder to act on mid-day.
Protein target (g/day) = Weight (kg) × 1.6 to 2.2
How This Calculator Computes Your Result
Enter your stats and training status above, using either path from Step 1. We apply the deficit and protein formulas, then adjust the messaging in your result based on your training status, since recomposition is more realistic for some starting points than others.
Step 4: Factor In Body Fat and Training Status
Recomposition is most realistic for beginners, returning trainees, or people with higher body fat percentages, they can often lose fat and build muscle at the same time. It’s still possible for lean, already-trained individuals, but progress is typically much slower, which we reflect in your result based on your training status.
A Note on Accuracy
Body recomposition is the slowest of the goal-based approaches, set pace expectations honestly. Resistance training is a stated prerequisite, the calorie and protein numbers alone don't build or preserve muscle without a training stimulus. No single validated recomposition formula exists, so this builds around the two levers with the strongest evidence: a modest deficit and adequate protein.
Frequently Asked Questions
Why is the deficit smaller than other weight-loss calculators?
A large calorie deficit works against building or maintaining muscle. Recomposition uses a smaller deficit, about 10 to 20% below TDEE, so you're losing fat slowly enough that your body can still support muscle growth or preservation with adequate protein and training.
Why is my protein target a range instead of one number?
Protein needs for preserving or building muscle in a deficit fall in a range, 1.6 to 2.2 g/kg bodyweight per day, depending on training experience, body fat level, and individual factors¹. We show a range and a per-meal breakdown rather than pretending to more precision than the evidence supports.
Is body recomposition realistic for everyone?
It's most realistic for beginners, returning trainees, or people with higher body fat percentages, since they can often lose fat and gain muscle at the same time. It's still possible for lean, already-trained individuals, but progress is typically much slower, this calculator reflects that through your training-status input.
Do I still need to lift weights for this to work?
Yes. Resistance training is a prerequisite, not optional. The calorie and protein targets create the right conditions, but a training stimulus is what actually signals your body to build or preserve muscle.
Sources
Evidence-Based Recommendations for Natural Bodybuilding Contest Preparation: Nutrition and Supplementation, Helms, Aragon & Fitschen, 2014
Higher Compared With Lower Dietary Protein During an Energy Deficit Combined With Intense Exercise Promotes Greater Lean Mass Gain and Fat Mass Loss, Longland et al., 2016
Body Recomposition Calculator
Use this body recomposition calculator to find calorie and protein targets for losing fat while building muscle.
Updated August 8, 2026
Calculated instantly in your browser — nothing is sent to or stored on our servers.
Medical Disclaimer: This calculator provides a general estimate based on established research and is for educational purposes only, not a substitute for medical advice. Individual results can vary based on health conditions, so consult a qualified healthcare professional or registered dietitian before making significant changes to your diet, exercise, or health routine. Read our full Medical Disclaimer.
How Body Recomposition Is Calculated
Most goal-based calculators on this site pick a lane: a deficit for fat loss, a surplus for muscle gain. Body recomposition asks for both at once, which is a genuinely harder target, and no single validated formula exists for it. This calculator instead builds around the two levers the evidence actually supports.
What This Calculator Measures
This gives you a calorie target and a protein target designed to support simultaneous fat loss and muscle retention or growth. It does not replace a training program, resistance training is what makes recomposition possible in the first place.
Step 1: Determine Your TDEE
You can either enter your daily calorie target directly, or let us estimate it from your stats using the same Mifflin-St Jeor and activity-multiplier method used by our TDEE Calculator.
Step 2: Apply a Small Deficit
Rather than a large deficit, we apply a smaller one, roughly 10 to 20% below your TDEE. Aggressive deficits work against simultaneous muscle building, so recomposition trades speed for a better shot at holding onto, or gaining, muscle while losing fat.
Calorie target = TDEE × (0.80 to 0.90)
Step 3: Set a Protein Target
We set protein at 1.6 to 2.2 g per kg of bodyweight per day, roughly 0.7 to 1 g per lb, the range with the strongest support for preserving or building muscle in a calorie deficit¹, a finding also demonstrated directly in a randomized trial of resistance-trained men in a marked energy deficit². We also break this into a rough per-meal count, since one large daily number is harder to act on mid-day.
Protein target (g/day) = Weight (kg) × 1.6 to 2.2
How This Calculator Computes Your Result
Enter your stats and training status above, using either path from Step 1. We apply the deficit and protein formulas, then adjust the messaging in your result based on your training status, since recomposition is more realistic for some starting points than others.
Step 4: Factor In Body Fat and Training Status
Recomposition is most realistic for beginners, returning trainees, or people with higher body fat percentages, they can often lose fat and build muscle at the same time. It’s still possible for lean, already-trained individuals, but progress is typically much slower, which we reflect in your result based on your training status.
A Note on Accuracy
Body recomposition is the slowest of the goal-based approaches, set pace expectations honestly. Resistance training is a stated prerequisite, the calorie and protein numbers alone don't build or preserve muscle without a training stimulus. No single validated recomposition formula exists, so this builds around the two levers with the strongest evidence: a modest deficit and adequate protein.
Frequently Asked Questions
Why is the deficit smaller than other weight-loss calculators?
A large calorie deficit works against building or maintaining muscle. Recomposition uses a smaller deficit, about 10 to 20% below TDEE, so you're losing fat slowly enough that your body can still support muscle growth or preservation with adequate protein and training.
Why is my protein target a range instead of one number?
Protein needs for preserving or building muscle in a deficit fall in a range, 1.6 to 2.2 g/kg bodyweight per day, depending on training experience, body fat level, and individual factors¹. We show a range and a per-meal breakdown rather than pretending to more precision than the evidence supports.
Is body recomposition realistic for everyone?
It's most realistic for beginners, returning trainees, or people with higher body fat percentages, since they can often lose fat and gain muscle at the same time. It's still possible for lean, already-trained individuals, but progress is typically much slower, this calculator reflects that through your training-status input.
Do I still need to lift weights for this to work?
Yes. Resistance training is a prerequisite, not optional. The calorie and protein targets create the right conditions, but a training stimulus is what actually signals your body to build or preserve muscle.
Sources
Evidence-Based Recommendations for Natural Bodybuilding Contest Preparation: Nutrition and Supplementation, Helms, Aragon & Fitschen, 2014
Higher Compared With Lower Dietary Protein During an Energy Deficit Combined With Intense Exercise Promotes Greater Lean Mass Gain and Fat Mass Loss, Longland et al., 2016