📄 Genetic Potential Calculator PDF
Download free printable FFMI calculator worksheet. Calculate your natural muscle-building potential offline with step-by-step formulas and interpretation guide.
This comprehensive 4-page PDF provides everything you need to calculate your genetic FFMI potential offline. Perfect for coaches, trainers, or anyone who prefers pen-and-paper tracking over digital tools.
The worksheet includes step-by-step calculation formulas, measurement guides, percentile classification charts, and interpretation tables. No internet connection required once downloaded.
Download Calculator PDF
Complete FFMI calculation worksheet with formulas and interpretation guide
What's Included in the PDF
FFMI Calculation Worksheet
Step-by-step formula with labeled fields for height, weight, body fat percentage, and final FFMI result.
Percentile Classification Chart
Compare your FFMI against population percentiles from 10th to 99th. See where you rank among natural lifters.
Natural Limit Estimation Table
Height-based predictions for maximum natural bodyweight at various body fat percentages (5-18% BF).
Body Composition Tracking Log
12-week measurement tracker to record weight, body fat, lean mass, and FFMI changes over time.
💡 How to Use the Calculator PDF
Step 1: Gather Your Measurements
- Accurate height (measured in morning, without shoes)
- Current bodyweight (morning weight, fasted)
- Body fat percentage (use calipers, DXA scan, or visual estimation)
Step 2: Complete the Worksheet
- Follow the step-by-step formula on Page 1
- Calculate lean body mass (total weight - fat mass)
- Divide by height squared to get raw FFMI
- Apply height normalization adjustment (provided formula)
Step 3: Interpret Your Results
- Reference the percentile chart on Page 2
- Check natural limit table on Page 3 for your height
- Track progress on the 12-week log (Page 4)
Tip: Print multiple copies to track progress every 4-6 weeks. Compare FFMI changes to ensure you're gaining lean mass, not just body fat.
Formulas Included in PDF
1. Lean Body Mass Calculation
LBM = Total Weight × (1 - Body Fat %)
Example: 180 lbs at 15% BF = 180 × (1 - 0.15) = 153 lbs lean mass
2. Raw FFMI Formula
FFMI = Lean Mass (kg) / Height (m)²
Example: 70 kg lean mass / (1.78 m)² = 22.1 raw FFMI
3. Normalized FFMI (Height Adjustment)
Normalized FFMI = FFMI + 6.1 × (1.8 - Height in meters)
This adjusts for height differences, allowing fair comparison between tall and short lifters.
4. Maximum Natural Prediction (Berkhan Formula)
Maximum Stage Weight (kg) = Height (cm) - 100
Predicts maximum contest weight at 5-6% body fat for natural competitors.
⚠️ Measurement Accuracy Requirements
Body fat percentage is the most error-prone measurement. FFMI calculations are only as accurate as your body fat estimate.
Body fat measurement methods (by accuracy):
- Most accurate: DXA scan (±2-3% error)
- Very good: Hydrostatic weighing (±3-4% error)
- Good: 7-site caliper test by trained professional (±4-6% error)
- Moderate: Bioelectrical impedance (±5-8% error)
- Poor: Visual estimation or online calculators (±8-15% error)
A 5% body fat measurement error can shift your calculated FFMI by 2-3 points. For example:
- Actual 15% BF measured as 10% → FFMI appears 2 points higher than reality
- Actual 15% BF measured as 20% → FFMI appears 2 points lower than reality
For most accurate results, use consistent measurement methods and track trends over time rather than focusing on single data points.
Online vs Offline Calculator
Use the PDF Worksheet When:
- No internet access: Gym, training camp, or travel situations
- Coaching multiple clients: Print copies for each athlete
- Prefer pen and paper: Physical tracking feels more tangible
- Long-term progress logs: Want physical records spanning months/years
- Teaching others: Demonstrate FFMI calculation process step-by-step
Use the Online Calculator When:
- Want instant results: No manual calculations needed
- Need visualization: Automatic percentile charts and graphs
- Comparing multiple scenarios: Quick "what-if" testing
- Mobile access: Calculate on phone anytime
Best practice: Use both! Online calculator for quick checks, PDF worksheet for detailed tracking and progress logs.
Frequently Asked Questions
Do I need to sign up or provide an email?
No. Direct download, no registration required. 100% free forever.
Can I print multiple copies?
Yes. Print unlimited copies for personal use or coaching clients.
What if I don't know my body fat percentage?
The PDF includes visual estimation guidelines, but for accurate FFMI, invest in a proper body fat measurement (calipers or DXA scan recommended).
Is this the same formula used in the online calculator?
Yes. Identical formulas. The PDF version simply requires manual calculation.
Can I share this PDF with others?
Share the download link from this page. Don't redistribute the PDF file directly on other websites.