Body Fat Calculator

Choose one of the five methods below to calculate your body fat percentage.

Calculate using:

Estimate your body fat percentage using your calculated BMI and standard body measurements.


Estimate your body fat percentage using the U.S. Navy method, which uses neck, waist, and hip circumference measurements.

Circumference Measurements:

Estimate your body fat percentage using the Jackson & Pollock 3-site skinfold method, which uses three measurements taken with skinfold calipers.

Skinfold Measurements:

Estimate your body fat percentage using the Jackson & Pollock 4-site skinfold method, which uses four measurements taken with skinfold calipers.

Skinfold Measurements:

Estimate your body fat percentage using the Jackson & Pollock 7-site skinfold method, which uses seven measurements taken with skinfold calipers.

Skinfold Measurements:


Body fat percentage: %
Body fat category: 
Calculated BMI: 
Body fat weight: lb
Lean body mass: lb
Body Fat Categorization per the American Council on Exercise highlighting the   category.
Body Fat Categorization per the American Council on Exercise[1]

How to Calculate Body Fat

Health and body weight are closely tied together. However, your percentage of body fat is just as much, if not more important, than body weight alone.

This is because body fat, not just body weight, is associated with chronic health issues such as heart disease, diabetes, hypertension, and even some cancers. In fact, studies have found that individuals with a normal BMI but a high body fat percentage are at an increased risk for prediabetes and type 2 diabetes.[2]

This makes sense from a practical standpoint. An athlete that weighs 180 pounds with 20% body fat and a high amount of lean muscle is much healthier than someone who weighs 180 pounds but is sedentary and has 40% body fat.

There are a number of ways to determine body fat. This includes direct measurement in a medical setting as well as measurements that can be done at home.

Body Fat Percentage

First, it is important to understand what body fat percentage means. Determining your total body composition takes into account your lean muscle mass, body fat percentage, bone mass, and water weight.

Infographic showing healthy body composition with the ideal body fat, lean muscle, bone, water, and organ mass

Research has found that body fat percentage is a better indicator of obesity-related health conditions such as coronary heart disease risk than waist circumference.[3] Higher levels of body fat also have a stronger association with cardiovascular disease risk and mortality when compared to BMI.[4]

Another study from European Heart Journal found that individuals with high amounts of body fat but normal weight, as reported by BMI, still had a high prevalence of cardiometabolic dysregulation, metabolic syndrome, and CV risk factors.[5] This makes maintaining a healthy body fat percentage extremely important.

How to Measure Body Fat

There are several different methods used to determine body fat. Each comes with its own benefits and drawbacks.

Measuring At Home

There are several easy methods for measuring body fat pretty accurately at home.

U.S. Navy/Army Body Fat Method

The U.S. Navy/Army body fat formula only requires you to measure your waist and neck circumference. This can then be used in a formula to determine your body fat percentage.

The benefit of this method is that it only requires a tape measure, so it is cheap and quick to do from home.

While it is not as accurate as direct measurements such as a DXA scan, studies have shown the error rate to still be relatively low, around 2.5-5%. This is still more accurate than many bioelectrical impedance methods.

To measure waist circumference, wrap the tape measure around the narrowest part of your waist. This is midway between your bottom rib and top of the hip bone, right around the navel.

For neck circumference, measure right above the Adam’s apple.

For women, hip circumference is also used. The measuring tape should be placed around the hips so that it passes over the greatest protrusion of the hips as viewed from the side.

These numbers can then be used in the following equation:

U.S. Navy Body Fat Formula

body fat = [86.010 × log10(waist – neck)] – [70.041 × log10(height)] + 36.76

body fat = [163.205 × log10(waist + hip – neck)] – [97.684 × log10(height)] – 78.387

A recent 2019 study found that this formula had slightly higher values for both muscle mass and body fat ratio in both genders and across all BMI categories when compared to bioelectrical impedance.

However, the differences were not statistically significant, illustrating that these are both fairly reliable ways to estimate body fat percentage.[6]

Since this is a rather complicated formula, it can be much easier to plug your measurements into a body fat calculator instead.

BMI Body Fat Method

Body mass index, or BMI, is widely used to estimate body fat based on height and weight.

BMI = weight [kg]height² [m²]

Imperial Units

BMI = weight [lb]height² [in²] × 703

Once you figure out your BMI, this can then be used in the formula below to calculate your body fat percentage. Unlike BMI, these formulas are different based on gender.

BMI Body Fat Formula

body fat = (1.20 × BMI) + (0.23 × age) – 16.2

body fat = (1.20 × BMI) + (0.23 × age) – 5.4

BMI is a useful way to calculate body fat percentage because you can also use it as a predictive formula if you are trying to figure out your ideal body weight. A 2016 study found that you can use a target BMI to compute ideal body weight.[7]

This would then allow you to plug that BMI into the equation to not only determine an ideal weight, but also an ideal body fat percentage.

IBW [lb] = 5 × BMI + ((BMI ÷ 5) × (height − 60 [in]))

Skinfold Method (3, 4, & 7 Site Jackson & Pollock methods)

Another at-home method that is affordable and relatively reliable is using a body fat caliper to measure skinfold thickness. These measurements are then used in different body fat equations depending on how many areas of the body you measure.

For the three-site method, the areas measured are different for males and females.


  • Chest
  • Abdomen
  • Thigh


  • Triceps
  • Suprailium
  • Thigh

The four-site method is the same for males and females and requires measurements of the tricep, suprailium, abdominal, and thigh areas.

In the seven-site method, the areas measured are the same for both men and women.

  • Triceps
  • Chest/Pectoral
  • Midaxillary
  • Subscapular
  • Suprailiac
  • Abdominal
  • Thigh

The trickiest part of using body fat calipers is ensuring that you measure the correct area and pinch the appropriate amount of fat. This takes practice and should be done several times to ensure consistent results.

You will need to pinch the skin into a fold and then place the calipers around the skinfold to get your final measurement.

Taking a skinfold measurement with calipers to calculate body fat
Methods for measuring skinfolds in various body areas for body fat calculation.
Site How To Measure
Tricep Vertical measurement at the midpoint of the tricep between shoulder and elbow with arm relaxed at the side.
Chest Diagonal measurement halfway between the anterior axillary (armpit) line and the nipple.
Subscapular Diagonal fold approximately 2 centimeters from the inferior angle of the scapula.
Midaxillary Midaxillary line horizontal to xiphoid process of the sternum.
Suprailiac Diagonal fold parallel and above the iliac crest.
Abdominal Vertical or horizontal fold 2 centimeters to the right of the navel.
Thigh Midpoint vertical fold of the front side of the upper leg between the patella (kneecap) and top of thigh.

One of the drawbacks of using skinfold thickness is that it can be difficult to properly measure the correct amount of fat. You may need help from someone in measuring and recording the numbers, especially for more hard-to-reach spots on your body.

Once you have your skinfold measurements, you can then plug these into either the 3, 4, or 7 site skinfold thickness calculator to determine your estimated body fat percentage.

The error range varies, although some studies have found error rates ranging from an overprediction of 10% to an underprediction of over 15%.[8] However, ensuring that you are consistent with your measurements can aid you in tracking your body fat percentage over time to at least monitor trends in loss or gain of body fat.

These calculations are rather complicated and differ between men and women, which makes using an automated calculator the easiest means to calculate body fat percentage when using the skinfold method.

The skinfold thickness of each site is first used to compute body density. These numbers are then used to determine body fat percentage. If you prefer to do the math yourself, the equations are as follows:

3-Site Body Fat Percentage Formula

Pectoral, Abdominal, and Thigh thickness in millimeters:

body density = 1.10938 – (0.0008267 × sum of skinfolds) + (0.0000016 × (sum of skinfolds)²) – (0.0002574 × age)

Tricep, Suprailiac, and Thigh thickness in millimeters:

body density = 1.0994921 – (0.0009929 × sum of skinfolds) + (0.0000023 × (sum of skinfolds)²) – (0.0001392 × age)

body fat = (495 ÷ body density) – 450

4-Site Body Fat Percentage Formula

Abdominal, Tricep, Thigh, and Suprailiac thickness in millimeters

body density = (0.29288 × sum of skinfolds) – (0.0005 × (sum of skinfolds)²) + (0.15845 × age) – 5.76377

Abdominal, Tricep, Thigh, and Suprailiac thickness in millimeters

body density = (0.29669 × sum of skinfolds) – (0.00043 × (sum of skinfolds)²) + (0.02963 × age) + 1.4072

body fat = (495 ÷ body density) – 450

7-Site Body Fat Percentage Formula

Chest, Axila, Tricep, Subscapular, Abdominal, Suprailiac, and Thigh thickness in millimeters

body density = 1.112 – (0.00043499 × sum of skinfolds) + (0.00000055 × (sum of skinfolds)²) – (0.00028826 × age)

Chest, Axila, Tricep, Subscapular, Abdominal, Suprailiac, and Thigh thickness in millimeters

body density = 1.097 – (0.00046971 × sum of skinfolds) + (0.00000056 × (sum of skinfolds)²) – (0.00012828 × age)

body fat = (495 ÷ body density) – 450

Measuring With Specialized Equipment

There are several methods for measuring body fat using specialized equipment and cannot be done at home.

Underwater Weighing

Underwater weighing used to be the gold standard for determining body fat percentage. Since muscle and bone are more dense and fat is more buoyant, someone with a higher body fat will weigh less underwater.

Using this principle, a person is first weighed on dry land. Next, they sit on a special scale as they are submerged underwater and asked to exhale all the air from their lungs and stay motionless while their weight is measured.

This procedure is repeated three times and averaged. A special calculation is then used to determine lean weight and fat weight and determine the percentage of body fat.[9]


A DEXA scan, also sometimes abbreviated DXA, is short for dual X-Ray absorptiometry.
A DEXA scan is often associated with determining someone’s bone mineral density; however, it also measures all components of your body composition. It works by sending a low x-ray beam that calculates soft tissue and bone density.

The DEXA scan then provides you with an analysis of your body composition based on the density of your fat, muscle, and bone.

Bod Pod

A Bod Pod is an egg-shaped piece of equipment that measures your body volume and the volume of gas contained within your chest to determine your body density. This then calculates your percentage of body fat and lean body mass.

Bioelectrical Impedance

Bioelectric impedance is a widely available method for use at home or the gym to determine body fat percentage. These machines require you to stand (and sometimes hold) onto electrodes that use a low voltage electric current to assess body composition.

However, these scales are less accurate than other methods and still use calculations based on age, sex, and height to compute body fat percentage. Studies have found that bioelectrical impedance data is actually of lower quality than waist circumference or BMI for detecting metabolic risk factors (4) and can have an error rate of up to 8%.[10]

Normal Body Fat Percentage

After you calculate your body fat, you can then compare this to the chart for healthy body fat percentages. This will differ between males and females. According to the American Council on Exercise, body fat categories are as follows:

Body fat categories for men and women defined by the American Council on Exercise.
Men Women
Essential Fat 10-13% 2-5%
Athletes 14-20% 6-13%
Fitness 21-24% 14-17%
Average 25-31% 18-25%
Obese >32% 25%

Normal Body Fat Percentage For Men vs. Women

There are clear differences in what constitutes a healthy body fat range depending on if you are male or female. This is due to the fact that there is a certain fat percentage that is required for basic physiologic functions.

Body fat is also dependent on genetics and hormone fluctuations. Since women require more body fat for bearing children, they naturally have higher amounts to serve as essential fat.

For a group of people with the same BMI, women typically present with roughly 10% higher body fat compared to men, which accounts for the differences in body fat percentages that are considered healthy in men and women.

How Much Body Fat Do I Have?

As you can see, there are a number of different methods to calculate your body fat percentage. At this time, the most accurate appears to be DEXA scanning, as this gives you an actual measurement of fat, bone, and lean muscle tissue by using an X-ray scanner.

However, most people do not have access to high-tech machines and need a way to not only measure their body fat, but also to continually monitor body composition trends over time. The above formulas provide affordable and easy ways to achieve this.

By keeping track of your body fat percentage, you can ensure that you are maintaining not only a healthy weight, but also a healthy total body composition.


  1. The American Council on Exercise, What are the guidelines for percentage of body fat loss?,
  2. Gómez‐Ambrosi, J., Silva, C., Galofré, J. C., Escalada, J., Santos, S., Gil, M. J., Valentí, V., Rotellar, F., Ramírez, B., Salvador, J., & Frühbeck, G., Body adiposity and type 2 diabetes: increased risk with a high body fat percentage even having a normal BMI, Obesity, 2011, 19(7), 1439-1444.
  3. Dervaux, N., Megnien, J. L., Chironi, G., & Simon, A., Comparative associations of adiposity measures with cardiometabolic risk burden in asymptomatic subjects, Atherosclerosis, 2008, 201(2), 413-417.
  4. Romero-Corral, A., Somers, V. K., Sierra-Johnson, J., Korenfeld, Y., Boarin, S., Korinek, J., Jensen, M., Parati, G., & Lopez-Jimenez, F., Normal weight obesity: a risk factor for cardiometabolic dysregulation and cardiovascular mortality, European heart journal, 2010, 31(6), 737-746.
  5. Hemmingsson, E., Uddén, J., & Neovius, M., No apparent progress in bioelectrical impedance accuracy: validation against metabolic risk and DXA, Obesity, 2009, 17(1), 183-187.
  6. Shaheen, A., Javed, N., Azam, F., Liaquat, A., Khan, M., Alam, S. M., & Mumtaz, S., Comparison of bioelectrical impedance and navy seal formula to measure body composition in medical students, Cureus, 2019, 11(5),
  7. Peterson, C. M., Thomas, D. M., Blackburn, G. L., & Heymsfield, S. B., Universal equation for estimating ideal body weight and body weight at any BMI, The American journal of clinical nutrition, 2016, 103(5), 1197-1203.
  8. Peterson, M. J., Czerwinski, S. A., & Siervogel, R. M., Development and validation of skinfold-thickness prediction equations with a 4-compartment model, The American journal of clinical nutrition, 2003, 77(5), 1186-1191.
  9. Quinn, E., How to Measure Body Fat With Hydrostatic Underwater Weighing, Verywell Fit,
  10. Lichtenbelt, W. D. V. M., Hartgens, F., Vollaard, N. B., Ebbing, S., & Kuipers, H., Body composition changes in bodybuilders: a method comparison, Med Sci Sports Exerc, 2004, 36, 490-497.