Body Fat Calculator

Body fat is an important element in successful weight control. Body fat requires fewer calories than muscle. So, the less fat/more muscle we have, the more calories we can eat before gaining weight. Body fat is often expressed as our "Body Fat Percentage" or "Body Fat Percent." Body fat percentage is the amount of body-fat-tissue as a percentage of total body weight. If your total body weight is 160 pounds and you have 32 pounds of fat, your body fat percentage is 20 percent.

Calculating Body Fat

Why Calculate Body Fat?

The higher your percentage of fat above average levels, the higher your health risk for weight-related illness, like heart disease, high blood pressure, gallstones, type 2 diabetes, osteoarthritis, and certain cancers. Also, the higher your percentage of fat (and the smaller your percentage of muscle) the less calories you need to maintain your weight and therefore the easier it is to gain weight. This is because muscle is more metabolically active than fat tissue.

Accurate Ways to Calculate Body Fat

• Home Body Fat Scales
• Skinfold Calipers (Callipers)
• Body Circumference Measurements
• Bioelectrical Impedance Analysis
• Electrical Impedance Myography
• 3D Body Scanners

This list does not include methods available exclusively in settings that aren’t available to the average person, such as in research labs.

Home Body Fat Scales

Home body fat scales are among the most readily available tools for calculating body fat percentage.  They are notoriously inaccurate and typically aren’t recommended when any real accuracy level is required.

Skinfold Callipers

This method of body fat calculation uses calipers to measure the thickness of a person’s subcutaneous fat in various locations throughout the body. It is a method that has been used for over half a century.  It requires you to measure the thickness of the fat under your skin’s surface in 3 to 7 different places.  These places are very specific and depend on whether you are a man or a woman. This is a quick and affordable test that can be conducted at home. It has an average measurement error rate of 3 to 3.5 percent body fat when conducted by someone experienced and who understands anatomy well enough to measure the right locations.

Body Circumference Measurements

Everybody has their own unique body shape.  Measuring the circumference of various parts of your body can help to reveal your body fat percentage.  This method is the one described above with the helpful body fat calculator tool. Body circumference measurements is the method used by many official organizations, including the US Army. As long as it is done properly and the measurements are accurate, it is very affordable, and its error rate is as low as 2.5 to 4.5 percent.

Bioelectrical Impedance Analysis (BIA)

Bioelectrical impedance analysis (BIA) devices use small electrical currents in the body to measure the depth of fat and therefore calculate the percentage on your body as a whole.  This is a very quick and easy method.  Researchers use this method, but devices are sold on the consumer market. The main problem is that most consumer devices are far less accurate than those used in medical and research settings. Quality devices have a rate of error of about 3.8 to 5 percent body fat, but that may be considerably higher in a consumer device.

Electrical Impedance Myography (EIM)

Electrical Impedance Myography (EIM) also uses small electrical currents as a body fat calculator tool. Though formerly available only to doctors and researchers, more recently, affordable devices have hit the consumer market.  It is quick and easy to use, simply placing it against various designated parts of the body.  That said, there isn’t much known about how accurate these devices may be, particularly among those sold to consumers. One study indicated that there is a 2.5 to 3 percent error rate among medical versions of the device but this has yet to be replicated and further research is needed.

3D Body Scanners

3D body scanners form a detailed image of your body shape using infrared sensors.  These sensors use infrared wavelengths of light to create a 3D model of your unique body. There are many different types of device, each of which has its own requirements for the process.  Overall, the process should take several minutes.  This process can then allow for an estimation of body fat. There are a number of consumer grade devices available, but they are expensive.  Moreover, each method has its own accuracy rates.  Those available to consumers are not likely to be as accurate as those meant for research labs, which have been found to have an error rate of around 4 percent.