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Skinfold Body Fat Calculator

Health

Estimate body fat percentage from 3-site skinfold measurements using the Jackson-Pollock formula and Siri equation, with sex-specific calculations.

Reviewed by the thecalcu.com team · Last updated July 12, 2026

Sex
Age
years
Chest Skinfold
mm
Abdomen Skinfold
mm
Thigh Skinfold
mm

Use skinfold calipers to pinch and measure each site to the nearest 0.5 mm. Sites differ by sex per the Jackson-Pollock 3-site protocol.

Body Fat Percentage

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Estimate only. Jackson-Pollock 3-site skinfold results depend on measurement technique and caliper accuracy — for clinical accuracy, use DEXA or hydrostatic weighing.

What is a Skinfold Body Fat?

A Skinfold Body Fat Calculator estimates your body fat percentage using the Jackson-Pollock 3-site method, a field technique that measures skin and subcutaneous fat thickness at three specific body locations with a handheld caliper. Unlike the Body Fat Calculator, which typically uses circumference-based formulas, this method relies on direct physical measurements of fat thickness, making it one of the more established approaches used by trainers, coaches, and sports scientists outside of clinical lab settings.

The method works by converting your three skinfold measurements, combined with age and sex, into an estimate of body density using a validated regression equation. That density figure is then converted into a familiar body fat percentage using the Siri equation. Because fat distribution differs between men and women, the calculator uses different measurement sites and formulas for each: chest, abdomen, and thigh for men; triceps, suprailiac, and thigh for women.

Skinfold testing sits between simple estimation tools and expensive lab methods like DEXA scanning in terms of both cost and accuracy. It requires a caliper and some practice, but in experienced hands it delivers meaningfully more individualized results than formulas based on height and weight alone, such as the BMI Calculator.

Why Use a Skinfold Body Fat Calculator?

Height-and-weight-based tools like BMI can't distinguish muscle from fat, which frustrates athletes and anyone with an above-average muscle mass. Skinfold testing directly measures subcutaneous fat, giving a more individualized body composition picture without the cost of a DEXA scan or hydrostatic weighing session.

This is particularly useful for tracking body recomposition over time, as you lose fat or build muscle, skinfold thickness at each site changes in ways a bathroom scale alone can't reveal. Athletes preparing for a competition, or anyone following a structured training program alongside a TDEE Calculator-based nutrition plan, can use repeated skinfold measurements to verify that a calorie deficit is actually reducing fat rather than lean mass.

Who Should Use This Calculator?

Personal trainers and coaches who already own skinfold calipers can use this tool to quickly convert raw site measurements into a body fat percentage without manual formula lookup. Athletes and bodybuilders tracking body recomposition during a cutting or bulking phase benefit from a more direct fat estimate than weight-based tools provide. Fitness enthusiasts who want a more precise alternative to circumference-based estimates from the Body Fat Calculator can use this if they have access to a caliper. People preparing for a physique competition where body fat percentage is closely tracked will find the site-specific detail useful. Anyone curious about the relationship between BMI and true body composition can compare their skinfold result against their BMI Calculator score to see how closely the two align for their body type.

What Insights Does the Skinfold Body Fat Calculator Give You?

Body Fat Percentage is the primary output, your estimated proportion of total body weight that is fat tissue, derived from the Siri equation. This is the number most people track over time, and the calculator displays it alongside standard category bands (Essential Fat, Athletic, Fit, Acceptable, Obese) that differ for men and women. Body Density is the intermediate physical measurement, in grams per cubic centimeter, calculated directly from your skinfold sum and age using the Jackson-Pollock regression equation. While body fat percentage is the more intuitive figure, body density is the more direct physical measurement and can be useful if you're comparing results against other body composition methods that report density rather than percentage.

How to use this Skinfold Body Fat calculator

  1. Select your Sex, the calculator uses different measurement sites and formulas for men and women.
  2. Enter your Age in years.
  3. Using a skinfold caliper, measure Site 1 (Chest for men, Triceps for women) in millimeters and enter the value.
  4. Measure Site 2 (Abdomen for men, Suprailiac for women) and enter the value.
  5. Measure Site 3 (Thigh, for both sexes) and enter the value.
  6. Review your Body Fat Percentage result and category badge, along with the calculated Body Density figure, to understand where you fall relative to typical fitness benchmarks.
Show formula & methodology ↓Show less ↑

Formula & Methodology

The calculator sums your three skinfold measurements (Sum3, in mm) and applies the sex-specific Jackson-Pollock 3-site regression equation to estimate body density:

Men: Body Density = 1.10938 − (0.0008267 × Sum3) + (0.0000016 × Sum3²) − (0.0002574 × Age)

Women: Body Density = 1.0994921 − (0.0009929 × Sum3) + (0.0000023 × Sum3²) − (0.0001392 × Age)

Body density is then converted to body fat percentage using the Siri equation:

Body Fat % = (495 ÷ Body Density) − 450

Worked example: For a 30-year-old man with skinfold measurements of 12 mm (chest), 15 mm (abdomen), and 14 mm (thigh):
- Sum3 = 12 + 15 + 14 = 41 mm
- Body Density = 1.10938 − (0.0008267 × 41) + (0.0000016 × 41²) − (0.0002574 × 30)
- Body Density ≈ 1.10938 − 0.03389 + 0.00269 − 0.00772 ≈ 1.0705
- Body Fat % = (495 ÷ 1.0705) − 450 ≈ 462.4 − 450 ≈ 12.4%

This places the individual in the Fit to Athletic range on standard body fat category charts.

Frequently Asked Questions

What is the Jackson-Pollock 3-site skinfold method?
It's a body composition estimation technique that uses a caliper to measure skin thickness at three specific body sites, then plugs those measurements into a validated regression formula to estimate body density and, from that, body fat percentage. It was developed by Jackson and Pollock in the 1980s and remains one of the most widely used field methods for estimating body fat outside a lab.
Which three sites are measured for men versus women?
For men, the standard 3-site protocol measures the chest, abdomen, and thigh. For women, the protocol instead measures the triceps, suprailiac (just above the hip bone), and thigh, since fat distribution patterns differ by sex.
How accurate is skinfold body fat testing?
In the hands of an experienced, consistent tester, skinfold testing typically estimates body fat within about 3–4% of more precise lab methods like DEXA scanning. Accuracy drops significantly with inconsistent caliper technique, so using the same tester and measurement sites each time produces more reliable trend data than absolute precision.
What is the difference between body density and body fat percentage?
Body density is an intermediate physical measurement, in grams per cubic centimeter, that reflects the ratio of fat to lean tissue in the body, fat tissue is less dense than muscle and bone. The Siri equation then converts this density figure into the body fat percentage most people are familiar with, using the formula (495 ÷ Body Density) − 450.
How does skinfold testing compare to the RFM Calculator?
Skinfold testing requires a caliper and hands-on technique but tends to produce more individualized estimates since it directly measures subcutaneous fat at multiple sites. The [RFM Calculator](/rfm-calculator/) only needs a tape measure and height, making it far more accessible, though it relies on a simpler waist-to-height formula rather than direct fat measurement.
How do I use the Skinfold Body Fat Calculator?
Select your sex, enter your age, then measure and enter the three skinfold thicknesses in millimeters using a body fat caliper at the sites indicated for your sex. The calculator instantly returns your estimated body density and body fat percentage.
What equipment do I need to take skinfold measurements?
You need a skinfold caliper, a handheld tool that pinches a fold of skin and subcutaneous fat and reads the thickness in millimeters. Basic plastic calipers are inexpensive and adequate for personal tracking, while spring-loaded metal calipers offer more consistent pressure for repeated measurements.
Can I take skinfold measurements on myself?
Yes, but self-measurement is less accurate than having a trained partner take the readings, particularly for sites like the back of the thigh that are hard to reach and pinch consistently. If precise tracking matters to you, consider having the same person measure you each time to reduce technique-related variability.
What body fat category do the results fall into?
The calculator displays your estimated body fat percentage alongside standard category bands, Essential Fat, Athletic, Fit, Acceptable, and Obese, which differ for men and women due to natural differences in essential fat levels. These bands provide context for whether your result falls within a typical, athletic, or higher-risk range.
Is this calculator a substitute for a professional body composition assessment?
No, skinfold measurements, even when taken carefully, are an estimate that depends heavily on tester technique and calipers used. For clinical-grade accuracy, methods like DEXA scanning, hydrostatic weighing, or Bod Pod air displacement plethysmography are more reliable, and this tool should not replace guidance from a healthcare provider.
Why does age factor into the skinfold formula?
The Jackson-Pollock equations include an age term because body fat distribution and skin compressibility change with age, affecting the relationship between skinfold thickness and total body fat. Including age improves the formula's accuracy compared to using skinfold thickness alone.
How often should I retake skinfold measurements to track progress?
Every 3–4 weeks is generally a reasonable interval, since body composition changes gradually and more frequent testing mainly captures measurement noise rather than real change. Taking measurements at a consistent time of day, using the same sites and technique, will make comparisons across sessions more meaningful.
Also known as
skinfold calculatorJackson Pollock body fat3-site skinfold testcaliper body fat calculatorbody density calculatorSiri equation calculator