4-Site Skinfold Body Fat Calculator (Durnin & Womersley)

Manish Kumar — Wed, 13 Aug 2025 05:02:02 +0000

4-Site Skinfold Calculator: Durnin & Womersley Body Fat Assessment

📐 4-Site Skinfold Calculator

Calculate your body fat percentage using the classic Durnin & Womersley (1974) 4-site skinfold method

Professional Assessment Tool: This calculator uses the gold-standard Durnin & Womersley 4-site skinfold method validated by sports scientists and fitness professionals worldwide.

🎂 Age

Age in years (16-72 years old for Durnin & Womersley equations)

👤 Gender

Required for accurate body fat calculation (different equations used)

📐 Measurement Units

Choose your preferred measurement unit for skinfold measurements

💪 Biceps

Vertical fold on front of upper arm over biceps muscle

🔧 Triceps

Vertical fold on back of upper arm over triceps muscle

🎯 Subscapular

Diagonal fold below the shoulder blade

⚡ Suprailiac

Diagonal fold above the hip bone (iliac crest)

4-Site Skinfold Calculator: Complete Durnin & Womersley Guide

The Durnin & Womersley (1974) 4-site skinfold method is the classic gold standard for body fat assessment using calipers. This scientifically validated protocol provides accurate body composition analysis using four measurement sites: biceps, triceps, subscapular, and suprailiac. Measurements can be taken in millimeters (mm) or inches with automatic conversion for precise calculations.

📏 Classic 4-Site Protocol

The Durnin & Womersley method uses four specific skinfold sites for both men and women. Research demonstrates this approach with high correlation coefficients compared to hydrostatic weighing across diverse populations. For comprehensive fitness guidance, explore our body fat percentage chart and visual body fat assessment guide.

🔬 Age-Specific Equations

Uses age-specific logarithmic equations for different age groups (16-19, 20-29, 30-39, 40-49, 50+ years). Studies validate the age-specific approach for improved accuracy across the lifespan.

⚖️ Universal Sites

All Participants: Biceps, Triceps, Subscapular, Suprailiac
Unlike other methods, Durnin & Womersley uses the same four sites for both genders, making it simpler to administer.

📊 Body Fat Standards by Age and Gender

Category	Men (18-29)	Men (30-49)	Men (50+)	Women (18-29)	Women (30-49)	Women (50+)
Essential Fat	2-5%	2-5%	2-5%	10-13%	10-13%	10-13%
Athletes	6-13%	7-16%	9-18%	14-20%	16-23%	18-27%
Fitness	14-17%	17-19%	19-21%	21-24%	24-27%	27-30%
Average	18-24%	21-27%	24-29%	25-31%	28-34%	31-37%
Above Average	25%+	28%+	30%+	32%+	35%+	38%+

📐 4-Site Measurement Instructions

💪 Biceps Skinfold

Location: Vertical fold on the front of the upper arm

Technique: Measure over the belly of the biceps muscle, midway between the acromion and olecranon processes

Direction: Fold runs parallel to the long axis of the arm

🔧 Triceps Skinfold

Location: Vertical fold on the back of the upper arm

Technique: Measure over the triceps muscle, midway between acromion and olecranon

Direction: Fold runs parallel to the long axis of the arm

🎯 Subscapular Skinfold

Location: Diagonal fold below the inferior angle of the scapula

Technique: Fold follows the natural line of the skin, approximately 45° to horizontal

Direction: Diagonal fold running medially downward

⚡ Suprailiac Skinfold

Location: Diagonal fold above the iliac crest

Technique: Measure at the anterior axillary line, above the iliac crest

Direction: Fold follows the natural line of the skin

🧮 Durnin & Womersley Formula & Protocol

4-Site Skinfold Calculation Steps

Step 1: Take Measurements

• Use calibrated skinfold calipers (Lange, Harpenden, or similar)

• Take 3 measurements at each site, use median value

• Apply 10g/mm² pressure consistently

• Read measurement 2 seconds after full pressure applied

Step 2: Calculate Body Density (Age-Specific Equations)

Men (Durnin & Womersley, 1974):

16-19 years: BD = 1.1620 - (0.0630 × log₁₀(Sum)) 20-29 years: BD = 1.1631 - (0.0632 × log₁₀(Sum)) 30-39 years: BD = 1.1422 - (0.0544 × log₁₀(Sum)) 40-49 years: BD = 1.1620 - (0.0700 × log₁₀(Sum)) 50+ years: BD = 1.1715 - (0.0779 × log₁₀(Sum))

Women (Durnin & Womersley, 1974):

16-19 years: BD = 1.1549 - (0.0678 × log₁₀(Sum)) 20-29 years: BD = 1.1599 - (0.0717 × log₁₀(Sum)) 30-39 years: BD = 1.1423 - (0.0632 × log₁₀(Sum)) 40-49 years: BD = 1.1333 - (0.0612 × log₁₀(Sum)) 50+ years: BD = 1.1339 - (0.0645 × log₁₀(Sum))

Step 3: Convert to Body Fat %

Body Fat % = ((4.95 ÷ Body Density) - 4.50) × 100

Using the Siri equation (1961)

Example: 25-year-old male, measurements: Biceps 6mm, Triceps 10mm, Subscapular 12mm, Suprailiac 8mm
Sum = 36mm, log₁₀(36) = 1.556, BD = 1.0647, Body Fat = 15.9%
Result: Fitness category for age group

💡 Measurement Tips & Best Practices

🎯

Proper Technique

Pinch skin and fat away from muscle. Maintain 10g/mm² pressure. Take measurements on right side of body. Ensure consistent technique across all four sites.

⏰

Timing Considerations

Measure at same time of day. Avoid post-exercise or post-meal measurements. Ensure proper hydration status for consistency.

🔄

Reliability

Take 3 measurements per site, use median value. Repeat measurements if values differ by >2mm. Train for consistency across sessions.

📏

Equipment Quality

Use calibrated calipers (±0.5mm accuracy). Popular brands: Lange, Harpenden, Accu-Measure. Regular calibration ensures measurement accuracy.

⚖️ Method Comparison & Historical Significance

The Durnin & Womersley (1974) method is considered the foundational work in skinfold body composition assessment. Historical analysis shows its lasting impact:

Method	Year	Sites	Age Groups	Sample Size	Correlation (r)
Durnin & Womersley	1974	4 sites	5 groups	481 subjects	0.92-0.97
Jackson & Pollock (Men)	1978	3 sites	Continuous	403 subjects	0.91
Jackson, Pollock & Ward (Women)	1980	3 sites	Continuous	249 subjects	0.84
Slaughter et al.	1988	2 sites	Youth only	310 subjects	0.89

Historical Significance:

First comprehensive age-specific skinfold equations
Established the 4-site measurement protocol
Validated across wide age range (16-72 years)
Used logarithmic transformation for improved accuracy
Foundation for subsequent skinfold research
Still widely used in clinical and research settings

🏥 Clinical Applications & Research Uses

Clinical Assessment

Applications: Obesity evaluation, weight loss monitoring, metabolic health assessment

Advantages: Non-invasive, cost-effective, no radiation exposure, suitable for repeated measurements

Research Applications

Uses: Population studies, intervention trials, epidemiological research, athletic performance studies

Benefits: Standardized protocol, age-specific equations, extensive validation literature

Population Studies

Scope: Large-scale health surveys, cross-cultural studies, longitudinal aging research

Value: Validated across diverse populations and ethnic groups

Limitations & Considerations

Factors: Requires trained technician, affected by hydration, assumes constant tissue density

Accuracy: ±3-4% standard error when performed correctly by experienced practitioners

References

Davidson LE, Wang J, Thornton JC, Kaleem Z, Silva-Palacios F, Pierson RN, Heymsfield SB, Gallagher D. Predicting fat percent by skinfolds in racial groups: Durnin and Womersley revisited. Med Sci Sports Exerc. 2011 Mar;43(3):542-9. doi: 10.1249/MSS.0b013e3181ef3f07. PMID: 20689462; PMCID: PMC3308342.
Peterson, M. J., Czerwinski, S. A., & Siervogel, R. M. (2003). Development and validation of skinfold-thickness prediction equations with a 4-compartment model. The American Journal of Clinical Nutrition, 77(5), 1186-1191. https://doi.org/10.1093/ajcn/77.5.1186
Chambers AJ, Parise E, McCrory JL, Cham R. A comparison of prediction equations for the estimation of body fat percentage in non-obese and obese older Caucasian adults in the United States. J Nutr Health Aging. 2014;18(6):586-90. doi: 10.1007/s12603-014-0017-3. PMID: 24950148; PMCID: PMC4396823.

Manish Kumar

Manish is a NASM-certified fitness and nutrition coach with over 10 years of experience in weight lifting and fat loss fitness coaching. He specializes in gym-based training and has a lot of knowledge about exercise, lifting technique, biomechanics, and more.

Through “Fit Life Regime,” he generously shares the insights he’s gained over a decade in the field. His goal is to equip others with the knowledge to start their own fitness journey.

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