Want to estimate your body fat percentage? Our free Body Fat Calculator uses your height, neck, waist, and hip measurements to estimate your body fat percentage.
Choose your preferred units and select your gender. Men need to enter their neck and waist measurements, while women also enter their hip measurement. The calculator then provides an estimated body fat percentage based on a circumference-based formula.
Body fat calculators provide an estimate and cannot replace professional body-composition testing. Your actual body fat percentage may differ depending on factors such as body shape, muscle mass, measurement technique, and the method used.
What Is a Body Fat Calculator?
A Body Fat Calculator estimates the percentage of your body weight that comes from body fat.
Unlike BMI, which compares your weight with your height, a body fat calculator uses body measurements to provide an estimate of your body composition.
This calculator uses a circumference-based method. The measurements required depend on your gender: men use height, neck, and waist measurements, while women also use a hip measurement.
How to Use the Body Fat Calculator
Using the calculator is simple:
- Choose Metric (cm) or Imperial (in) units.
- Select Male or Female.
- Enter your height.
- Enter your neck measurement.
- Enter your waist measurement.
- If you select Female, enter your hip measurement.
- Click Calculate.
The calculator will show your estimated body fat percentage.
How Is Body Fat Percentage Calculated?
Circumference-based body fat methods use measurements such as height, neck, waist, and hips to estimate body fat percentage. The U.S. Navy’s body-composition guidance also uses circumference measurements, with different measurement requirements for men and women.
For men, the calculation uses the difference between waist and neck measurements together with height.
For women, the calculation uses waist, hip, and neck measurements together with height.
Because this is an estimation method, the result can differ from measurements obtained using methods such as DEXA, hydrostatic weighing, or other professional body-composition testing.
Why Does the Calculator Ask for Neck, Waist, and Hip Measurements?
These measurements provide information about body size and fat distribution that a simple height-and-weight calculation cannot capture.
For men, the circumference-based method uses the waist and neck measurements along with height. For women, the method also includes the hip measurement. The Navy’s current guidance specifies neck, waist/abdominal, and hip measurements for women and neck plus abdominal measurements for men.
How Should You Take Your Measurements?
For a more useful estimate, try to measure consistently each time.
Use a flexible measuring tape and keep it reasonably level around the body. Avoid pulling the tape extremely tight or leaving it loose.
For the most consistent results, take measurements under similar conditions each time you use the calculator.
Small differences in where and how you place the tape can change the final estimate.
Body Fat Percentage vs. BMI
Body fat percentage and BMI are not the same thing.
BMI uses height and weight to place a person into a general weight category.
Body fat percentage attempts to estimate how much of your body weight consists of fat.
For example, someone with a lot of muscle may have a relatively high BMI without having a similarly high body fat percentage. BMI does not directly measure body fat.
Is the Body Fat Result Accurate?
The result should be treated as an estimate.
Circumference-based equations can be useful for getting a general idea of body fat, but they are affected by measurement technique, body shape, and individual differences.
For a more precise assessment, professional body-composition methods may be appropriate.
Why Can My Result Be Different From Another Calculator?
Different body fat calculators can use different formulas, measurements, and assumptions.
One calculator may use circumference measurements, while another may estimate body fat from BMI, age, and gender. Because the methods are different, the results may not match exactly.
For this reason, it is better to use the same calculator and measurement method when tracking changes over time.
Frequently Asked Questions
What measurements do I need for men?
Men need their height, neck circumference, and waist circumference.
What measurements do I need for women?
Women need their height, neck circumference, waist circumference, and hip circumference.
Can I use centimeters?
Yes. Select Metric (cm) and enter all measurements in centimeters.
Can I use inches?
Yes. Select Imperial (in) and enter all measurements in inches.
Does body fat percentage change over time?
Yes. Body composition can change as body weight, muscle mass, fat mass, activity, and other factors change.
Is body fat percentage better than BMI?
They measure different things. BMI is based on height and weight, while body fat percentage attempts to estimate the proportion of your weight that is fat. Neither measurement provides a complete picture of health by itself.
Why does the calculator ask for gender?
The circumference-based equations use different calculations for men and women because the measurement relationships used by the equations differ.
Disclaimer: This Body Fat Calculator provides an estimate for general informational purposes. It is not an official military body-composition assessment or a substitute for professional body-composition testing or medical advice. For the most useful comparison over time, take your measurements using the same technique and under similar conditions each time.