How to use this calculator
1. Enter your measurements to calculate your FFMI (an estimate of muscularity for your height). Add a photo if you like.
2. Select your training experience and move the time slider to explore potential muscle gain on the scale. Results are estimates.
3. See how much muscle you could gain with proper training and compare with other physiques.
NORMALIZED FFMI
Lean body mass: —
Muscularity Scale
02Reference photos show people of similar heights and body fat. Lighting, pump, posing, and genetics (muscle bellies and shape) affect how each person looks.
Your result will appear here.
What could the next few years look like?
PROJECTIONExplore Lyle McDonald’s muscle-gain model for men.
10–20 sets per muscle group per week, close to failure: 0–2 reps in reserve (RIR).
Support this with adequate nutrition: maintenance calories up to a 500-calorie daily surplus, and at least 0.8 g of protein per pound of body weight per day.
1 year from today
LBM: — now → — projected
Calculate your current FFMI first.
Your projected range will shade the number line below.The model and its assumptions
| Productive training year | Muscle gain per year (men) |
|---|---|
| First | 20–25 lb |
| Second | 10–12 lb |
| Third | 5–6 lb |
| Fourth onward | 2–3 lb |
McDonald’s model is a coaching estimate for natural lifters with effective training and nutrition. Female projections use exactly half the male gain rates. Experience means productive training, not simply years with a gym membership. Age, genetics and recovery affect results.
We advance through each training year, prorate partial years, and add modeled muscle to current fat-free mass at the same height. This height-normalized FFMI conversion is our illustration, not McDonald’s own FFMI prediction. Body fat and future appearance are not predicted. Extending the advanced rate is a short-term scenario, not unlimited lifetime growth.
Source: Lyle McDonald — Four Models for Genetic Muscular Potential ↗VISUALIZE YOUR PROGRESS
AI muscle preview
Explore an illustration of your potential progress using your own photo and selected muscle gain.
Your AI illustration will appear here.
Image generation is not connected yet.Generating a preview sends your photo to the AI image provider. No photo is sent until you choose Generate preview.
An AI illustration, not a prediction of your exact results. Pose, lighting, body fat and genetics affect appearance.