Body-recomposition calculator for planning simultaneous fat loss and muscle gain (recomp) — not a cut or bulk.
Four tabs: macro plan (mild 10-15% deficit, high protein), realistic expectations by training experience, timeline, and weekly progress tracker.
Disclaimer: Recomp works best for beginners and overweight individuals. Consult a coach or RD for personalization.
Calculator information
📋 How to use this calculator
- Macro Plan tab: enter weight (lb/kg), height (in/cm), age, sex, and activity level (sedentary/light/moderate/active) to compute TDEE using Mifflin-St Jeor.
- Set a light deficit of 10-15% below TDEE (recomp range, not a 20-25% cut) and protein at 0.7-1.0 g/lb (1.6-2.2 g/kg) to preserve muscle.
- Realistic Expectations tab: pick training experience (beginner/intermediate/advanced) for monthly muscle gain estimates (Lyle McDonald model) and simultaneous fat loss.
- Timeline tab: enter current and target body fat percentage to estimate recomp duration (typically 6-18 months).
- Progress Tracker tab: log weight and body measurements weekly; the tool computes a 4-week rolling average to filter out water-weight noise.
- Tip: Recomp works best for true beginners (first 12 months of training). Advanced lifters can recomp but gain muscle slowly - alternating cut and bulk cycles is usually more efficient.
🧮 Recomposition Macros & TDEE (Mifflin-St Jeor)
BMR_male = 10W + 6.25H - 5A + 5; BMR_female = 10W + 6.25H - 5A - 161; TDEE = BMR x activity_factor; Recomp_kcal = TDEE x 0.85-0.90
- W: weight in kg, H: height in cm, A: age in years
- Activity factor: 1.2 sedentary / 1.375 light / 1.55 moderate / 1.725 active
- Protein: 0.7-1.0 g/lb (1.6-2.2 g/kg) for natural lifters (ISSN 2017)
- Fat: at least 0.35-0.45 g/lb (0.8-1.0 g/kg) to support hormonal health
- Carbohydrates: remaining calories after protein and fat
Maximum natural muscle gain per Lyle McDonald: year 1 = 2-2.5 lb (0.9-1.1 kg)/month, year 2 = ~1 lb (0.45 kg)/month, year 3 = ~0.5 lb (0.22 kg)/month, year 4+ = ~0.2 lb (0.1 kg)/month.
💡 Worked example: Male, age 28, 165 lb (75 kg), 5'9" (175 cm), beginner lifter
Given:- Weight 75 kg (165 lb), height 175 cm (5'9"), age 28
- Activity moderate (4 gym sessions/week + ~8,000 steps/day)
- Body fat 22% (target 15%)
- Training experience: 8 consistent months
- Goal: simultaneous fat loss and muscle gain
Steps:- BMR = 10(75) + 6.25(175) - 5(28) + 5 = 750 + 1093.75 - 140 + 5 = 1708.75 kcal
- TDEE = 1708.75 x 1.55 = 2648 kcal
- Recomp calories (12% deficit): 2648 x 0.88 = 2330 kcal/day
- Protein: 75 x 2.0 = 150 g (600 kcal)
- Fat: 75 x 0.9 = 67 g (603 kcal)
- Carbs: (2330 - 600 - 603) / 4 = 282 g
- Expected fat loss: 0.7-1.1 lb (0.3-0.5 kg)/week at a light deficit
- Expected muscle gain (beginner): ~2 lb (0.9 kg)/month, mostly in the first 6 months
- Timeline to 15% BF: from 165 lb at 22% BF (36 lb fat) to ~26 lb fat while adding ~7-9 lb muscle = 6-9 months
Result: Eat 2330 kcal/day at 150P / 282C / 67F. Roughly 7 months to reach 15% body fat with body weight holding steady around 161-168 lb (73-76 kg).
❓ Frequently asked questions
Is body recomposition realistic?
Yes, particularly for: beginners in their first 12 months, lifters returning after a long break (muscle memory), overweight people with body fat above 20% (men) or 28% (women), and PED users. For intermediate-to-advanced natural lifters, recomp is very slow (0.2-0.5 lb / 0.1-0.2 kg of muscle per month) and the calorie deficit limits protein synthesis. Alternating 6-8 week mini-cuts with 3-4 month lean bulks is usually more efficient for advanced lifters.
How much protein do I need for recomp?
The International Society of Sports Nutrition (ISSN) recommends 0.7-1.0 g/lb (1.6-2.2 g/kg) of body weight for natural lifters. During a recomp deficit, aim for the high end - 0.9-1.1 g/lb (2.0-2.4 g/kg) - to maximize muscle protein synthesis. Spread it across 4-5 meals with at least 30 g of leucine-rich protein per meal. Good sources: whey, casein, eggs, lean meat, fish, tofu. A 165 lb (75 kg) man needs about 150-180 g/day.
What is the ideal calorie deficit for recomp?
A 10-15% deficit from TDEE (about 200-400 kcal/day) is optimal for recomp. Deficits above 20% impair protein synthesis and recovery, accelerating muscle loss. Under 10% is too slow for fat loss. Pair the deficit with progressive overload (add weight or reps weekly), 7-9 hours of sleep, and stress management. Beginners can recomp at a smaller 5-10% deficit.
Will my body weight drop during recomp?
Not by much. Recomp targets composition, not the scale. You might lose 2-7 lb (1-3 kg) over 6 months while looking dramatically leaner because fat (larger volume per pound) is replaced by muscle (smaller volume per pound). Track progress with photos, waist circumference, body-fat calipers, or a quarterly DEXA scan - not daily weigh-ins.
How long does recomp typically take?
Realistic recomp duration is 6-18 months depending on starting point. A man going from 22-25% BF to 12-15% BF usually takes 8-12 months. A woman going from 30% BF to 22% BF takes about 10-14 months. Beginners can move faster (6-9 months) thanks to newbie gains. Once you hit the target, transition to maintenance or a lean bulk for further muscle gain. Patience is the main lever - daily changes are invisible, but quarterly photos make the progress obvious.
📚 Sources & references
Last updated: May 11, 2026