Body Fat Percentage Calculator

Body fat percentage is the proportion of your body weight that comes from fat. The rest of your weight consists of muscle, bone, organs, water and other components known as lean mass. It's a better indicator of health and fitness than just weight or BMI because even if you weigh the same amount, the amount of body fat can vary dramatically. This calculator shows your body fat percentage in numbers and explains what this number means for your body.

What does body fat percentage mean?

A single percentage is meaningless without knowing the range of values it falls into. Even a 22% body fat level can be considered low for women while being on the high side for men, because women are biologically predisposed to store more essential fats.

Health organizations divide body fat percentage into various categories. The following table uses the classification of the American Council on Exercise (ACE) and this tool also uses that classification with color-coded results.

Essential fat is the minimum amount of body fat required to maintain hormonal production and overall health. The fit and average ranges are where most healthy, active people fall. The obese range indicates an increased risk for health problems and should be addressed.

The ideal body fat percentage for each age.

As we get older our body fat percentage will gradually increase. This is a normal phenomenon. Jackson and Pollock have published widely used reference values that give realistic goals for men and women in different age groups.

This calculator compares your age to these reference values and shows the ideal body fat percentage for you. It also calculates how much fat you need to reduce in order to reach this goal based on your current weight. If you are already below the reference value, it will show that as well.

Here's how to estimate your body fat percentage with this calculator:

Choose a method that allows you to measure the required data accurately. All three methods display their results in the same window which makes it easy to compare them.

The US Navy method uses a tape measure and is one of the most accurate methods for home use. Men need to measure their height, neck circumference, and waistline, while women also need to measure their hips. The formula uses inches.

Enter the values in either centimeters or inches. This calculator will convert them for you. For example, if a man has a waist circumference of 34 inches, neck circumference of 16 inches and height of 70 inches, then his difference between waist and neck is 18 inches, and his body fat percentage would be about 15.5.

The BMI method uses the Deurenberg equation to estimate body fat percentage from Body Mass Index and age. The input is easiest as only weight, height and age are required but accuracy decreases for people with very muscular builds or a very low body fat percentage.

1 is for males and 0 is for females. The BMI is calculated by dividing the weight (in kilograms) by the square of the height (in meters). As this method also has its limitations, this tool shows the values of the BMI method for comparability in another selection method so that you can see the difference between the results.

Do you already know your body fat percentage?

If you have measurements from a DEXA scan, smart body fat scale, Bod Pod or subcutaneous fat test, select the third method and enter those values directly.

This calculator skips the estimation and shows results directly. It displays categories, fat mass and lean mass, the Lean Mass Index (LMI), and an age-appropriate ideal body fat percentage. This is the fastest way to turn a simple percentage into useful information that can help guide your actions.

Fat mass, fat-free mass, FFMI.

When body fat percentage and weight are known, this calculator will break down the weight into fat mass and lean mass. Fat mass is the value obtained by multiplying the weight by the body fat percentage, while lean mass makes up the rest.

Continuously tracking these two values is more helpful than just weighing yourself as it's possible to see a significant improvement in body composition even if the weight barely changes when you gain muscle and lose fat at the same time.

The Fat Free Mass Index (FFMI) is calculated by dividing the fat-free mass by the square of the height, similar to BMI which uses total weight. It measures how much muscle mass there is relative to height. For most men it ranges from 18-20 and for women 15-17 with trained athletes often being higher.

Measuring methods for optimal results:

If using a tape measure, opt for a soft one and lay it flat against your body. Be careful not to pull on the skin. Measure around your neck below the larynx. The waist is measured at the belly button in men or at the narrowest part of the waist in women. The hip measurement is taken at the widest point.

Take each measurement two to three times, average the results and measure at the same time of day daily for consistent tracking. Even small errors in measuring tape reading can lead to a significant difference from your actual body fat percentage.

What is possible with these estimates and what isn't.

All home methods are estimates and not laboratory results. When measurements are taken quickly, using a tape measure can result in errors of several percentage points. In addition, for people with very low body fat, very muscular or older, the accuracy of the results is reduced because it assumes a typical distribution of fat.

Gold standard methods such as DEXA scans, underwater weighing and Bod Pods are more accurate but must be done in a medical facility. Skinfold calipers fall somewhere in between and also require some practice. If you use one method regularly, pick one and measure the same way each time, don't over-interpret individual values and instead look at trends.

This calculator is for general educational purposes only and does not constitute medical advice. The body fat percentage estimated by the tape measure method or BMI is an approximation only and should not replace a qualified health professional's judgment. Consult your doctor before changing your diet, exercise program, or weight.