FatCalc

Body Fat Calculator

Use this body fat calculator to estimate your body fat percentage and discover how much you would need to weigh for a healthy amount of body fat. The calculator uses formulas based on the U.S. Navy, BMI, and skinfold measurement methods to calculate body fat.

Your results will be shown integrated with charts developed by three well-known health and fitness organizations. They will show your status at your current weight. You can then plan for a goal weight to put you in a desired healthy body fat percentage range.

Body Fat Calculator

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What is a healthy body fat percentage?

In general, a healthy body fat percentage range for women is 21 to 35 percent and for men it's 8 to 24 percent.

Healthy Body Fat Percentages
AgeWomenMen
20 to 3921 to 32 %8 to 19 %
40 to 5923 to 33 %11 to 22 %
60 to 7924 to 35 %13 to 24 %

The above table was derived from a study by Dympna Gallagher et al., based on a new approach for developing body fat percentage ranges. It links healthy BMI guidelines established by the National Institutes of Health and the World Health Organization with predicted body fat percentages.

How to Estimate Body Fat?

Several different technologies capable of accurately measuring your body's composition exist, but they can be expensive and inconvenient to use. This online calculator will give you a quick and reasonable estimate of your body fat percentage.

You can choose different measurement methods from the calculator's drop-down list to calculate your body fat percentage. One is based on your Body Mass Index, a body circumference method developed by the U.S. Navy, and four skinfold measurement methods.

If you already know your body fat percentage and are confident of its accuracy, you can enter the value manually. You can then note your status in the charts.

Estimate from BMI

This method calculates body fat percentage from Body Mass Index (BMI) using regression equations. The formula takes sex and age into consideration.

This estimation is not as accurate as body circumference or skinfold methods. It does, however, give a ballpark estimate for those of you who don't want to bother with measuring tapes or skinfold calipers. Note also that it's only intended for sedentary individuals.

U.S. Navy Body Circumference Method

This calculation relies on circumference measurements at the neck, waist, and hips. Use a measuring tape made of nonstretchable material, preferably fiberglass. Measure your circumferences parallel to the floor, applying the same amount of tension at the same spot each time you make a measurement. Don't compress the underlying soft tissues. All measurements, including height and weight, should be made while in thin underclothes and without shoes. In this way, it will provide you with a consistent estimate on which to chart your progress.

Circumference measurements are taken differently for men and women. The formula does not require hip measurements for men. Take waist measurements at the belly button for men and above the belly button for women. Click on the help (?) icon next to the input fields for measurement details.

The accuracy of the U.S. Navy Body Circumference method is comparable to skinfold methods, around 3.5% for most people.

Skinfold Measurement Methods

Skinfold testing can predict body fat percentages within plus or minus 3.5 percent of your actual body composition. Generally, the more skinfold sites measured, the greater the accuracy. However, the U.S. Navy body circumference method and skinfold testing can lose accuracy for obese or extremely lean individuals.

For skinfold measurements, please refer to your skinfold caliper manual for instructions. As a general rule, skinfold measurements should always be taken from the right side of the body.

Take a minimum of two measurements at each skinfold site. If the two measurements differ by more than 2 mm, take a 3rd. Record the average for the site.

Click the help (?) icon next to the input fields for info on the exact location of the skinfold measurement.

Jackson-Pollock 3-Site Skinfold Method

This is a simple method that you can perform yourself. It is reasonably accurate for most people with an average build. However, it tends to underestimate body fat for athletes, bodybuilders, or very lean individuals.

The formula uses the chest, abdomen, and thigh for men and the tricep, suprailiac, and thigh for women.

Jackson-Pollock 4-Site Skinfold Method

With this method, the skinfold measurement sites are the same for both males and females. Four sites are used, making this method slightly more reliable than the three sites, but it loses accuracy for very lean individuals.

Jackson-Pollock 7-Site Skinfold Method

This method produces the most reliable results of the three Jackson-Pollock series of skinfold measurements. The test uses seven skinfold sites, which are the same for both males and females.

Durnin-Womersley Skinfold Method

The Durnin-Womersley method is probably the most popular skinfold measurement method used, but it overestimates body fat for very fit individuals. It utilizes four skinfold measurements at the same four skinfold sites for both males and females.

Body Fat Percentage Calculation Results

The results of the calculations will show your body fat percentage status in charts developed by the American Council on Exercise, the NIH Health / Guidelines, and the American College of Sports Medicine.

The tables will include a weight column showing a calculated weight range for each body fat range. From this, you should ascertain what you would need to weigh to fall into any of the other categories. The weight ranges are only accurate if you gain or lose weight in such a way as to maintain your current lean mass. In essence, the weight ranges reflect only changes in body fat.

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References

  1. Obesity and overweight
    World Health Organization
  2. Development of the DoD Body Composition Estimation Equations.
    Hodgdon, James A.; Friedl, Karl
    NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA
  3. Generalized equations for predicting body density.
    Jackson, A.S., Pollock, M.L.
    British Journal of Nutrition. 40: 497-504, 1978.
  4. The effect of sex, age and race on estimating percentage body fat from body mass index.
    Jackson AS, Stanforth PR, Gagnon J, Rankinen T, Leon AS, Rao DC, Skinner JS, Bouchard C, Wilmore JH.
  5. Healthy percentage body fat ranges: An approach for developing guidelines based on body mass index.
    Gallagher D, Heymsfield SB, Heo M, Jebb SA, Murgatroyd PR, Sakamoto Y.
  6. Body Composition Changes in Weight Loss: Strategies and Supplementation for Maintaining Lean Body Mass, a Brief Review
    Darryn Willoughby, Susan Hewlings and Douglas Kalman

Last Update: October 20, 2021 18:18 UTC