Muscle Gain Rate Projection
Calculator
Results
- Final lean mass
- 60.143786 kilograms
- Total gain
- 2.143786 kilograms
- Current annual gain rate
- 5%
- Average weekly gain
- 0.041226 kilograms
Projected path over the weeks
- Lean mass
- Baseline lean mass
Week-by-week schedule
| 1 | 58.06 | 0.06 | 0.06 | 58.00 |
| 2 | 58.11 | 0.11 | 0.06 | 58.00 |
| 3 | 58.17 | 0.17 | 0.05 | 58.00 |
| 4 | 58.22 | 0.22 | 0.05 | 58.00 |
| 5 | 58.27 | 0.27 | 0.05 | 58.00 |
| 6 | 58.32 | 0.32 | 0.05 | 58.00 |
| 7 | 58.38 | 0.38 | 0.05 | 58.00 |
| 8 | 58.43 | 0.43 | 0.05 | 58.00 |
| 9 | 58.48 | 0.48 | 0.05 | 58.00 |
| 10 | 58.53 | 0.53 | 0.05 | 58.00 |
| 11 | 58.58 | 0.58 | 0.05 | 58.00 |
| 12 | 58.63 | 0.63 | 0.05 | 58.00 |
| 13 | 58.67 | 0.67 | 0.05 | 58.00 |
| 14 | 58.72 | 0.72 | 0.05 | 58.00 |
| 15 | 58.77 | 0.77 | 0.05 | 58.00 |
| 16 | 58.81 | 0.81 | 0.05 | 58.00 |
| 17 | 58.86 | 0.86 | 0.05 | 58.00 |
| 18 | 58.91 | 0.91 | 0.05 | 58.00 |
| 19 | 58.95 | 0.95 | 0.04 | 58.00 |
| 20 | 58.99 | 0.99 | 0.04 | 58.00 |
| 21 | 59.04 | 1.04 | 0.04 | 58.00 |
| 22 | 59.08 | 1.08 | 0.04 | 58.00 |
| 23 | 59.12 | 1.12 | 0.04 | 58.00 |
| 24 | 59.16 | 1.16 | 0.04 | 58.00 |
| 25 | 59.21 | 1.21 | 0.04 | 58.00 |
| 26 | 59.25 | 1.25 | 0.04 | 58.00 |
| 27 | 59.29 | 1.29 | 0.04 | 58.00 |
| 28 | 59.33 | 1.33 | 0.04 | 58.00 |
| 29 | 59.37 | 1.37 | 0.04 | 58.00 |
| 30 | 59.40 | 1.40 | 0.04 | 58.00 |
| 31 | 59.44 | 1.44 | 0.04 | 58.00 |
| 32 | 59.48 | 1.48 | 0.04 | 58.00 |
| 33 | 59.52 | 1.52 | 0.04 | 58.00 |
| 34 | 59.55 | 1.55 | 0.04 | 58.00 |
| 35 | 59.59 | 1.59 | 0.04 | 58.00 |
| 36 | 59.63 | 1.63 | 0.04 | 58.00 |
| 37 | 59.66 | 1.66 | 0.04 | 58.00 |
| 38 | 59.70 | 1.70 | 0.04 | 58.00 |
| 39 | 59.73 | 1.73 | 0.03 | 58.00 |
| 40 | 59.77 | 1.77 | 0.03 | 58.00 |
| 41 | 59.80 | 1.80 | 0.03 | 58.00 |
| 42 | 59.83 | 1.83 | 0.03 | 58.00 |
| 43 | 59.87 | 1.87 | 0.03 | 58.00 |
| 44 | 59.90 | 1.90 | 0.03 | 58.00 |
| 45 | 59.93 | 1.93 | 0.03 | 58.00 |
| 46 | 59.96 | 1.96 | 0.03 | 58.00 |
| 47 | 59.99 | 1.99 | 0.03 | 58.00 |
| 48 | 60.02 | 2.02 | 0.03 | 58.00 |
| 49 | 60.05 | 2.05 | 0.03 | 58.00 |
| 50 | 60.08 | 2.08 | 0.03 | 58.00 |
| 51 | 60.11 | 2.11 | 0.03 | 58.00 |
| 52 | 60.14 | 2.14 | 0.03 | 58.00 |
Comparison
| Scenario | Final lean mass | Total gain |
|---|---|---|
| Doing nothing | 58.00 | 0.00 |
| Your plan | 60.14 | 2.14 |
Formula
rate(t) = year-1 rate ÷ 2^(training age in years); lean(w) = lean(w−1) × (1 + rate/52)= 2.14
Note
These are deliberately simplified models. They assume a constant rate and ignore metabolic adaptation, water weight, hormones, illness, medication, sleep and stress, so individual results vary widely — two people following the same plan can land far apart. The 7700 kcal per kilogram of body fat figure is a population average, not a personal constant. A large deficit, a fast mileage or load ramp, or a very low target body fat can be harmful; treat any flagged rate as a reason to slow down. This is NOT medical, dietetic or coaching advice — consult a qualified doctor, registered dietitian or accredited coach before acting on any projection here, and especially if you are pregnant, under 18, or managing any medical condition.
More in Health progress
See all →Frequently asked questions
What's a realistic rate of muscle gain per month?+
For a natural lifter, realistic rates are commonly cited as roughly 1-2% of body weight per month for beginners, slowing to a fraction of that for advanced lifters — the calculator should adjust its projection based on training experience, not just calorie surplus.
Why does muscle gain slow down so much after the first year of training?+
The body has a genetically limited capacity for muscle growth, and beginners are furthest from that ceiling, so they see the fastest initial gains — as you approach your natural potential, each additional pound of muscle takes progressively longer to build.
Does eating a bigger calorie surplus speed up muscle gain proportionally?+
No — muscle protein synthesis has a practical upper limit regardless of surplus size, so a very large surplus mostly adds fat once that limit is reached rather than accelerating muscle growth further.
How does training experience factor into this projection?+
Most models divide progress into beginner, intermediate, and advanced phases with progressively slower expected rates, since newly stressed muscle adapts faster than muscle that's already been trained consistently for years.
Why might my actual muscle gain be slower than the projection?+
Genetics, sleep quality, training consistency, protein intake, and hormonal factors (age, sex) all affect the realized rate — the calculator gives a population-level estimate, and individual results commonly land on either side of it.