About the Parillo Body Fat Method

The Parillo Caliper Method for calculating percent body fat is a simple method using nine skinfold site measurements. This is a very basic general formula with questionable accuracy, though it's very easy to perform. This formula does not take into account any differences between males and females, age differences, or individual physiological variations, which is why it may overestimate body fat by approximately 4.7% compared to scientifically validated methods like Jackson-Pollock or Durnin-Womersley.

Despite its limitations, the Parillo method remains popular among bodybuilders and fitness enthusiasts for tracking changes in body composition over time. When used consistently with proper measurement technique, it provides reliable data for monitoring progress during training cycles, competition preparation, or fat loss phases.

How to Use the Parillo Body Fat Calculator

Follow these steps to accurately calculate your body fat percentage using the Parillo 9-site method:

1. Gather Your Equipment

You'll need:

  • Skinfold Calipers: Harpenden or Lange calipers are considered most accurate, though Slimguide or Accu-Measure calipers work for tracking changes
  • Marker Pen: To mark measurement sites
  • Tape Measure: To locate anatomical landmarks
  • Recording Sheet: To note measurements

2. Take Your Measurements

All measurements should be taken on the right side of your body in millimeters (mm). The skinfold should be firmly grasped between thumb and index finger about 1 cm above the marked site, pulled away from the body, with calipers applied perpendicular to the fold. Wait 2 seconds before reading. Take each measurement 2-3 times and use the average.

3. Enter Data and Calculate

Input all nine skinfold measurements and your body weight into the calculator above. The calculator automatically sums your skinfolds, applies the Parillo formula, and provides your body fat percentage along with categorization and interpretation.

4. Interpret Your Results

The calculator provides:

  • Body Fat Percentage: Your calculated percentage
  • Category: From competition lean to above average
  • Fat Mass & Lean Mass: Breakdown of body composition
  • Interpretation: What your results mean for training and nutrition

Pro Tips for Accurate Measurements

Pro Tip: For the most reliable tracking, take measurements at the same time of day (preferably morning after using the bathroom, before eating or training), use the same calipers, and have the same person take measurements if possible. Consistency in technique matters more than absolute accuracy when tracking body composition changes during training phases.

The Parillo Formula and Methodology

The Formula

The Parillo equation is remarkably simple compared to other body fat formulas:

% Body Fat = (Sum of 9 sites × 27) ÷ Bodyweight (lbs)

Where:

  • Sum of 9 sites: Total of all skinfold measurements in millimeters
  • Constant 27: Parillo's derived multiplier based on bodybuilder population data
  • Bodyweight: Must be in pounds (lbs) for the formula to work correctly

The Nine Measurement Sites

The skinfold sites are: Chest, Abdominal, Thigh, Bicep, Tricep, Subscapular, Suprailiac, Lower Back, and Calf.

Why This Formula?

John Parillo developed this formula in the 1980s specifically for competitive bodybuilders. Unlike scientifically validated equations that account for age, gender, and population-specific factors, Parillo wanted a simple, universal formula that bodybuilders could use to track weekly changes during training cycles.

The method was validated through his work with numerous competitive bodybuilders, comparing skinfold measurements to visual assessments and competition results. While not scientifically rigorous, it proved practical for its intended purpose: monitoring body composition changes in athletes following structured training and nutrition programs.

Calculation Example

Let's walk through an example calculation for a male bodybuilder:

Measurements (mm):

  • Chest: 8 mm
  • Abdominal: 18 mm
  • Thigh: 15 mm
  • Bicep: 5 mm
  • Tricep: 10 mm
  • Subscapular: 12 mm
  • Suprailiac: 16 mm
  • Lower Back: 11 mm
  • Calf: 7 mm

Bodyweight: 180 lbs (81.6 kg)

Step 1: Sum all skinfolds = 8 + 18 + 15 + 5 + 10 + 12 + 16 + 11 + 7 = 102 mm

Step 2: Multiply by 27 = 102 × 27 = 2,754

Step 3: Divide by bodyweight = 2,754 ÷ 180 = 15.3% body fat

Result: This athlete is at approximately 15% body fat, which falls into the "lean" category typical for off-season bodybuilders or serious recreational athletes.

Accuracy and Limitations

Research indicates the Parillo method has several important limitations:

  • Overestimation: Studies show it may overestimate body fat by approximately 4.7% compared to validated methods like DEXA or hydrostatic weighing
  • No Gender Differentiation: Men and women have different essential fat levels and distribution patterns, which this formula ignores
  • No Age Adjustment: Body fat distribution changes with age, affecting measurement accuracy
  • Population-Specific: Developed for bodybuilders; may be less accurate for general population or athletes in other sports
  • Technique-Dependent: Results heavily influenced by measurement consistency and tester skill

However, for its intended purpose—tracking changes in body composition over time in athletes following structured programs—the Parillo method works well when used consistently.

Sport-Specific Applications for Athletes

Bodybuilding and Physique Competition

This is where the Parillo method originated and where it's most useful:

  • Competition Prep: Track weekly changes during 12-16 week prep phases. Bodybuilders typically aim for 3-6% body fat for men and 8-12% for women by competition day
  • Off-Season Monitoring: Maintain 8-12% for men and 15-20% for women during muscle-building phases to prevent excessive fat gain
  • Peak Week Strategy: Daily measurements during the final week to fine-tune water manipulation and carb loading protocols

Weight Class Sports

Athletes competing in weight classes can use the Parillo method for:

  • Wrestling: Monitor body composition during weight cutting phases; maintain optimal power-to-weight ratio at 6-10% for men, 12-18% for women
  • Boxing/MMA: Track fat loss while preserving strength and power; target 6-8% for men, 12-16% for women at weigh-in
  • Olympic Lifting: Optimize body composition within weight classes; men 8-12%, women 15-20% depending on class
  • Powerlifting: Balance strength gains with body fat management; varies widely by athlete and strategy

Team and Field Sports

While less critical than in physique or weight-class sports, body composition monitoring benefits athletes in:

  • Football: Different standards by position; skill players 8-12%, linemen 15-25%
  • Basketball: Target 6-10% for guards, 8-14% for forwards and centers
  • Soccer: Maintain 7-12% for men, 14-20% for women for optimal endurance and agility
  • Rugby: Position-dependent; backs 8-12%, forwards 12-18%

Professional Athlete Examples

Based on published data and visual assessments:

  • Bodybuilders (Competition): Phil Heath, Ronnie Coleman at competition reportedly 3-4% (though measurement methods vary)
  • Physique Competitors: Men's Physique competitors typically 5-7% on stage
  • Combat Sports: Georges St-Pierre maintained approximately 8-9% during his UFC career
  • Track Athletes: Elite sprinters typically 6-8% for men, 12-15% for women

Note: These are estimates from various sources and measurement methods. Direct comparison between methods is not always reliable.

Using Results for Training Planning

If Below Optimal Range (Too Lean):

  • Gradually increase calorie intake by 200-300 calories daily
  • Reduce cardio volume by 20-30%
  • Focus on strength training to build muscle mass
  • Monitor energy levels, hormones, and recovery

If Within Optimal Range (Maintaining):

  • Continue current training and nutrition protocols
  • Make small adjustments based on training phase and goals
  • Monitor weekly to ensure stability
  • Plan periodic mini-cuts or gaining phases as needed

If Above Optimal Range (Fat Loss Phase):

  • Create moderate calorie deficit (300-500 calories daily)
  • Increase protein to 1.0-1.2g per lb bodyweight to preserve muscle
  • Add 2-3 cardio sessions weekly (150-200 minutes total)
  • Maintain strength training volume to signal muscle retention
  • Aim for 0.5-1% body fat loss per week for sustainable progress

Seasonal Variations

Athletes should expect body fat to vary throughout the year based on training phases:

  • Pre-Season (Building Phase): 10-15% for men, 18-23% for women—focus on adding muscle and strength
  • In-Season (Competition Phase): 8-12% for men, 15-20% for women—maintain performance while staying lean
  • Off-Season (Recovery Phase): 12-18% for men, 20-25% for women—allow recovery while preventing excessive fat gain
  • Competition Prep (Peaking Phase): 5-8% for men, 12-16% for women—achieve competition-level leanness

Comparison to Other Body Fat Methods

Parillo vs. Jackson-Pollock

The Jackson-Pollock equations are scientifically validated formulas that account for age and gender:

  • Accuracy: Jackson-Pollock is more accurate, with error margins of ±3.5% vs. Parillo's ±4.7%
  • Sites: Uses 3 or 7 sites vs. Parillo's 9 sites
  • Calculation: More complex, uses body density calculation
  • Best For: General population and research settings

Parillo vs. Durnin-Womersley

Durnin-Womersley uses 4 sites with age-specific equations:

  • Sites: Only 4 sites (bicep, tricep, subscapular, suprailiac) vs. Parillo's 9
  • Speed: Faster to measure with fewer sites
  • Population: Better validated across different age groups
  • Best For: Quick assessments in clinical or fitness settings

Parillo vs. DEXA/Bod Pod

High-tech methods offer different advantages:

  • Accuracy: DEXA and Bod Pod generally more accurate (±2-3%)
  • Cost: Parillo is free after caliper purchase; DEXA/Bod Pod cost $50-150 per scan
  • Convenience: Parillo can be done at home weekly; high-tech methods require appointments
  • Regional Data: DEXA provides regional body fat distribution; Parillo only gives total
  • Best For: When absolute accuracy is critical or for medical purposes

Which Method Should You Use?

Choose based on your goals and circumstances:

  • Parillo: Bodybuilders tracking weekly changes during competition prep
  • Jackson-Pollock 3-site: General fitness enthusiasts wanting reliable estimates
  • Jackson-Pollock 7-site: Athletes wanting more comprehensive tracking
  • Durnin-Womersley: Quick assessments by trainers or in clinical settings
  • DEXA: When absolute accuracy is needed or for medical purposes
  • Bod Pod: Research settings or high-level athletic programs

⚠️ Important: Regardless of method chosen, consistency is key. Use the same method, same time of day, same tester when possible. The trend over time matters more than any single measurement.

The Science Behind Skinfold Measurements

Why Skinfolds Work

Skinfold measurements work because:

  • Subcutaneous Fat Correlation: About 50% of body fat is stored subcutaneously (under the skin), which correlates with total body fat
  • Regional Sampling: Taking measurements from multiple sites captures individual variation in fat distribution patterns
  • Practical Assessment: Provides a balance between accuracy, cost, and convenience for regular monitoring

Factors Affecting Accuracy

Several factors can influence skinfold measurement accuracy:

  • Hydration Status: Dehydration can make skinfolds appear thinner; take measurements in hydrated state
  • Tester Experience: Skill in locating sites and applying consistent pressure significantly affects results
  • Caliper Quality: Spring tension and calibration affect measurement precision
  • Recent Exercise: Blood flow and muscle pump can temporarily affect readings; measure before training
  • Time of Day: Morning measurements (after bathroom, before eating) tend to be most consistent
  • Menstrual Cycle: Women may see 2-4% variation due to water retention; track throughout full cycle

Measurement Best Practices

According to sports science expert Robert Wood, who has analyzed sports performance data for over 25 years, proper technique is critical:

  1. Mark Sites First: Use anatomical landmarks to mark all sites before beginning measurements
  2. Right Side Only: All measurements on right side for consistency (standard in North America)
  3. Proper Pinch: Grasp firmly 1cm above marked site, pull perpendicular to body surface
  4. Caliper Placement: Apply 1cm below fingers, perpendicular to fold
  5. Wait Time: Wait 2 seconds after applying pressure before reading
  6. Multiple Readings: Take 2-3 measurements per site, use median value
  7. Rotation: Measure all sites once before repeating to avoid tissue compression effects

Frequently Asked Questions

How accurate is the Parillo body fat method compared to other formulas?

The Parillo method may overestimate body fat by approximately 4.7% compared to validated methods like Jackson-Pollock or DEXA. However, when used consistently with proper technique, it's excellent for tracking changes over time rather than determining absolute body fat percentage. The method works best for bodybuilders and athletes who take weekly measurements during training cycles.

What are the 9 skinfold sites for the Parillo method and where exactly are they located?

The 9 sites are: Chest (diagonal fold between nipple and armpit), Abdominal (vertical fold 1 inch right of navel), Thigh (vertical fold midway between hip and knee), Bicep (vertical fold on front of upper arm), Tricep (vertical fold on back of upper arm), Subscapular (diagonal fold below shoulder blade), Suprailiac (diagonal fold above hip bone), Lower Back (diagonal fold above spine), and Calf (vertical fold on inner calf). See our individual skinfold site pages for detailed photos and instructions.

Who developed the Parillo body fat formula and when?

John Parillo, a bodybuilding coach and nutritionist, developed this formula in the 1980s specifically for competitive bodybuilders. It was published in his 1993 book "High-performance bodybuilding" (Berkeley Publishing Group). Parillo wanted a simple, practical formula that bodybuilders could use for weekly tracking during competition preparation, as opposed to more complex scientific formulas requiring age and gender adjustments.

Does the Parillo method work differently for men and women?

No, the Parillo formula uses the same calculation for both men and women, which is one of its limitations and why it may be less accurate than gender-specific formulas like Jackson-Pollock. Men and women have different essential fat levels (2-5% for men, 10-13% for women) and different fat distribution patterns. This simplicity makes Parillo easy to use but potentially less accurate, especially at very low or very high body fat percentages.

How often should I measure body fat with the Parillo method?

For bodybuilders and physique competitors during preparation phases, weekly measurements are recommended to track progress and make timely adjustments to diet and training. For general fitness and muscle-building phases, monthly measurements are sufficient. Always measure at the same time of day (preferably morning after bathroom use, before eating or training), use the same calipers, and if possible have the same person take measurements for consistency.

What's a good body fat percentage for bodybuilding competition?

For bodybuilding competition, men typically aim for 3-6% body fat (though measured values vary by method), while women target 8-12%. Men's Physique competitors are slightly higher at 5-7%. These are extremely low levels that are difficult to maintain and should only be reached temporarily for competition. Off-season body fat for bodybuilders is typically 8-12% for men and 15-20% for women to allow for optimal muscle building while maintaining health.

Can I take skinfold measurements on myself or do I need someone else?

While you can measure some sites yourself (abdominal, thigh, bicep, suprailiac, calf), several sites are difficult to reach accurately (subscapular, lower back). For most reliable results, have a trained person take all measurements. If self-measuring is necessary, consider using a 3-site or 4-site method like Jackson-Pollock where all sites are accessible. Consistency matters most—if self-measuring, always use the same technique and sites.

References

  1. Parrillo, J., Greenwood-Robinson, M. (1993). "High-performance bodybuilding." Berkeley Publishing Group, New York, pp. 169-172.
  2. Jackson, A.S., & Pollock, M.L. (1985). "Practical assessment of body composition." Physician and Sportsmedicine, 13(5), 76-90.
  3. Durnin, J.V., & Womersley, J. (1974). "Body fat assessed from total body density and its estimation from skinfold thickness." British Journal of Nutrition, 32(1), 77-97.
  4. American Council on Exercise. (2009). "ACE Personal Trainer Manual: The Ultimate Resource for Fitness Professionals." 4th Edition.
  5. American College of Sports Medicine. (2018). "ACSM's Guidelines for Exercise Testing and Prescription." 10th Edition.
  6. Heymsfield, S.B., Lohman, T.G., Wang, Z., et al. (2005). "Human body composition." 2nd ed. Human Kinetics, Champaign, IL.
  7. Norton, K., & Olds, T. (1996). "Anthropometrica: A textbook of body measurement for sports and health courses." UNSW Press, Sydney.
  8. Lee, R.C., Wang, Z., Heo, M., et al. (2000). "Total-body skeletal muscle mass: development and cross-validation of anthropometric prediction models." American Journal of Clinical Nutrition, 72(3), 796-803.

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