Calculator Inputs
Use the form below to estimate lean mass, daily protein range, and per meal distribution.
Example Data Table
| Example | Weight | Body Fat | Goal | Lean Mass | Protein Range | Target |
|---|---|---|---|---|---|---|
| Recreational lifter | 80 kg | 18% | Maintenance | 65.6 kg | 125–151 g/day | 139 g/day |
| Cutting athlete | 90 kg | 24% | Aggressive Cut | 68.4 kg | 198–233 g/day | 215 g/day |
| Body recomposition | 60 kg | 30% | Recomposition | 42.0 kg | 92–113 g/day | 102 g/day |
| Muscle gain phase | 72 kg | 15% | Muscle Gain | 61.2 kg | 129–159 g/day | 145 g/day |
Formula Used
Lean Mass = Body Weight × (1 − Body Fat % ÷ 100)
Protein Range = Lean Mass × Protein Multiplier
Protein per Meal = Daily Protein Target ÷ Meals per Day
This calculator uses lean mass as the protein anchor. It then adjusts the multiplier according to goal, activity level, age band, weekly training frequency, and intensity preference.
Typical multiplier bands in this tool range from 1.4 to 3.5 grams per kilogram of lean mass. Higher ranges are mainly reserved for harder cuts, older adults, and demanding training schedules.
How to Use This Calculator
- Enter your body weight and choose kilograms or pounds.
- Select whether lean mass should come from body fat or direct entry.
- If using body fat, enter a realistic estimate.
- Choose your activity level, goal, age band, and training days.
- Set meals per day to see protein per meal.
- Pick conservative, balanced, or high performance targeting.
- Press Calculate Protein to show results above the form.
- Use the CSV or PDF buttons to export your output.
Frequently Asked Questions
1. Why use lean mass instead of total body weight?
Lean mass focuses protein planning on metabolically active tissue. That often gives a more individualized estimate, especially when body fat levels vary widely between people.
2. Is this calculator good for fat loss phases?
Yes. It raises the protein multiplier when cutting, because preserving muscle becomes more important during energy restriction and harder training blocks.
3. What if I do not know my body fat percentage?
You can enter lean mass directly if you already have it from a scan, coach report, or previous assessment. Otherwise use a reasonable body fat estimate.
4. Does this replace medical nutrition advice?
No. It is a planning tool, not a diagnosis or prescription. Medical conditions and therapeutic diets need a clinician or registered dietitian.
5. Why does age change the recommendation?
Older adults can need slightly more protein to support muscle maintenance and anabolic response. The calculator reflects that with modest multiplier increases.
6. How should I use the per meal number?
Spread your target across the number of meals you usually eat. That helps structure daily intake instead of pushing most protein into one sitting.
7. Why is there a range instead of one fixed answer?
Protein needs vary with training stress, calorie intake, recovery demands, and personal preference. A range gives room for realistic planning and food choices.
8. Can I use this during muscle gain phases?
Yes. Choose muscle gain and a suitable activity level. The tool will estimate a lean mass based protein range that supports growth and recovery.