Body Fat Calculator

Biological Sex

Male

Female

Age

Weight

lbs

Height

Feet

Neck

inches

Waist

inches

Convert

What is the Body Fat Calculator?

Our Body Fat Calculator allows you to estimate the percentage of body fat in your body. This information is essential for understanding your overall health and fitness, as it provides insights beyond just simple weight measurements. Accompanied by other measures of physical fitness, such as BMI, we can get a better picture of our overall health.

Importance of Body Fat Percentage

You might want to know your body fat percentage to help you assess your fitness level, tailor your exercise and diet plans, and monitor the progress of your new diets and exercise routines. It is a more accurate measure of health than body weight alone, as it differentiates between fat and lean mass.

How to Use Our Body Fat Calculator

In order to use our Body Fat Calculator, you must start by choosing or filling in a variety of inputs. Before you start, make sure you have a tape measure handy, as you will need it to assess some values you might not be aware of yet.

#	Step	Description
1	Select Your Biological Sex	Choose between MALE or FEMALE.
2	Enter Your Age	Input your AGE in years.
3	Enter Your Weight	Choose either kilograms (KG) or pounds (LB) to input your weight.
4	Enter Your Height	Choose either centimeters (CM) or feet (FT) to input your height.
5	Enter Your Neck Circumference	Measure your neck circumference in inches. Choose inches and enter the measurement (for example, 16), or choose centimeters (CM). You will need the tape measure for this step.
6	Enter Your Waist Circumference	Measure your waist circumference in inches. Choose inches and enter the measurement (for example, 34), or choose centimeters (CM). You will need the tape measure for this step as well.
7	Enter Your Hip Circumference (Female Only)	For the FEMALE option, you also need to input your hip circumference, for which you will need the tape measure.
8	Click on CONVERT	After you do this step, your result will appear at the bottom of the page. It will be organized in a neat table, where you will get your result interpreted by two methods: the U.S. Navy Method and the BMI Method. Alongside this, you will also receive a breakdown of your body mass in the unit of weight of your choosing, as well as a categorization of your overall fitness and the ideal body fat percentage for your category.

Example Calculation

We will consider 2 examples below, to demonstrate the different formulae for each of them. Keep in mind that units matter for manual calculations: both examples use US units, so the U.S. Navy formulas take height and every circumference in inches, and the BMI formula takes weight in pounds and height in inches. In case you have values in other units, you must convert them first (1 inch = 2.54 cm, 1 kg = 2.2046 lb).

Example Calculation (U.S. Navy Method)

Let’s calculate the body fat percentage for Diego, a male, aged 30, weighing 176 lb, 5 ft 9 in (69 in) tall, with a neck circumference of 16 in and a waist circumference of 34 in:

Using the U.S. Navy method, the formula for calculating body fat percentage for men, with every measurement in inches, is:

BodyFatPercentage=86.010\timeslog10(WAIST-NECK)-70.041\timeslog10(HEIGHT)+36.76

Plugging in the values, we get:

BodyFatPercentage=86.010\timeslog10(34-16)-70.041\timeslog10(69)+36.76 =

86.010\timeslog10(18)-70.041\timeslog10(69)+36.76

Calculating the logarithmic values:

BodyFatPercentage=86.010\times1.25527-70.041\times1.83885+36.76

BodyFatPercentage= 15.93

His estimated body fat percentage is around 15.93%.

For women, the formula is different, because it also includes the hip circumference. It goes as follows, again with every measurement in inches:

BodyFatPercentage=163.205\timeslog10(WAIST+HIP-NECK)-97.684\timeslog10(HEIGHT)-78.387

Example Calculation (BMI Method)

The BMI method is slightly simpler to calculate manually. Let’s assess the body fat of Carla, a female, aged 22, weighing 120 lb, being 5 ft 6 in (66 in) tall, and having a waist measurement of 26 in, a hip measurement of 37 in, and a neck measurement of 15 in.

First, we calculate the BMI (see our BMI calculator for more details). With weight in pounds and height in inches, the formula multiplies by 703:

BMI= 703\timesWEIGHT\divHEIGHT^2 = 703\times120\div66^2 = 19.37

Now, we can plug the value into the BMI Method formula:

BODY FAT = 1.2xBMI+0.23xAGE-5.4​

BODY FAT = 1.2x19.37+0.23x22-5.4 = 22.90

Her body fat is estimated at 22.90%.

For males, the formula is a little different.

BODY FAT = 1.2xBMI+0.23xAGE-16.2

Courses of Action Based on Body Fat Percentage

Type	Description
Underfat	If your body fat percentage is below the essential fat level, you should consult a healthcare professional to prevent future health issues.
Healthy/Normal Fat	Maintain a balanced diet and regular physical activity to keep your body fat within this range.
Overfat	Improve your diet, increase physical activity, and possibly seek professional guidance to reduce body fat.
Obese	Consult a health care specialist to help you with developing a comprehensive weight loss plan.