This body fat percentage calculator determines body fat, the shape of your body but also lean body weight and BMI BMR values. You can discover more on this subject below the form.

Age: *
Weight: *
Height: *
Neck: *
Waist: *
Activity level: *

How does this body fat percentage calculator work?

This weight tool helps you discover personalized estimates of some of the most important weight constants, from body fat, lean weight to BMI, BMR and calorie requirements.

You are required to input the age, select the gender and then enter your weight, height and neck, waist measurements plus hip measure in the case of females.

In order for the calculation to come in hand you can select the measurement unit for some of the data, therefore choosing whether you want to work with lbs or kg, inches or centimeters.

This body fat percentage calculator uses the U.S Navy Method with the following formulas:

■ For men: 495/(1.0324-0.19077(Log(waist-neck))+0.15456(Log(height)))-450

■ For women: 495/(1.29579-0.35004(Log(waist+hip-neck))+0.22100(Log(height)))-450

Beside the body fat value you are also going to be returned the lean body weight, the body type, BMI and BMR values but also the minimum calorie requirement per day in order to maintain these figures.

Example calculation and result

■ Using the English tab, in case of a male, aged 35, weighing 210 lbs at a height of 6ft 1in with neck measurement of 21in and waist line 41in and moderately active:

- Your Body Fat is 18.1%;

- Body Fat: 17.24 kg;

- Lean Body Weight is: 78.01 kg;

- Your Weight is: Overweight;

- Your BMI is: 27.7;

- Your BMR is: 2,060.1 calories/day;

- Minimum Calorie requirement is: 3,193 daily calories/day.

■ Using the Metric tab, in case of a female, aged 28, weighing 93 kg at a height of 173cm with neck measurement of 42cm and waist line 86cm and hips 110cm and lightly active:

- Your Body Fat is 32.9%;

- Body Fat: 22.04 kg;

- Lean Body Weight is: 44.96 kg;

- Your Weight is: Healthy weight - Middle Normal ;

- Your BMI is: 23.2;

- Your BMR is: 1,472.6 calories/day;

- Minimum Calorie requirement is: 2,025 daily calories/day.

What is the body fat percentage?

This represents a measure of the fitness level of the body, an indicator of the body shape and it is usually obtained by dividing the estimated amount of body fat to the total body mass.

Women, unlike men usually have higher levels of body fat in every range because their bodies are prepared to resist in pregnancies but also because of their regulating hormones. Fat is also distributed differently throughout their bodies.

Body fat consists of essential fat, the one needed to maintain basic body processes and reserve or storage fat, the variable amount in the adipose tissues and the layers of the internal organs.

Body fat scales are used to monitor this value but you can also extract it through this online calculator.

Once you have the result you can assess whether this level is healthy for you and think of the next steps you should take if you want to lose some fat. The range of the body fat percentage as described by the The American Council on Exercise:

Description Women Men
Essential fat 10-13% 2-5%
Athletes 14-20% 6-13%
Fitness 21-24% 14-17%
Acceptable 25-31% 18-25%
Obese 32%+ 25%+

Which are the measurement techniques for body fat?

■ Using BMI - a person’s mass in kg divided by the square of the height in meters determines the BMI in the basic formula. This value can be correlated then through tables with the assessment of the body type but overall this is not a very accurate body fat prediction.

■ Using height and circumference - this is the U.S Navy method that compares waist and hips measurements to neck measurement and height. This method is also considerate inaccurate compared to other practical methods.

■ Underwater weighing - this method can determine body density quite accurately by submerging the person completely in water and calculating the volume of displaced water.

■ Body average density - determining the average density can then be used to determine fat content because fat density is lower than muscles and bones.

■ Skinfold - this is known as the pinch test in which a pinch of skin from several point of the body is measured using calipers to determine the subcutaneous thickness of fat.

■ Ultrasound - is the method used to determine tissue structure and it is currently one of the most accurate techniques to measure subcutaneous fat thickness.


1) Jackson AS, Stanforth PR, Gagnon J, Rankinen T, Leon AS, Rao DC, Skinner JS, Bouchard C, Wilmore JH. (2002) The effect of sex, age and race on estimating percentage body fat from body mass index: The Heritage Family Study. Int J Obes Relat Metab Disord; 26(6):789-96.

2) Siri WE. (1961) Body composition from fluid spaces and density: Analysis of methods. In Brozek J, Henzchel A. Techniques for Measuring Body Composition. Washington: National Academy of Sciences. pp. 224–244.

17 Dec, 2014