Body Fat Calculator

Calculate your body fat percentage using the U.S. Navy method and BMI-based estimation. Get lean mass, fat mass, and body composition category.

Results

23.5%
Average
U.S. Navy Method
17.6 kg
Fat Mass
57.4 kg
Lean Body Mass
BMI-based estimate: 20.1%

Body Fat Categories (Male)

Essential Fat
2-5%
Athlete
6-13%
Fitness
14-17%
Average
18-24%
Obese
25%+

How to Measure

  • •Waist: Measure at the narrowest point, typically at the navel level. Keep the tape horizontal and snug but not compressing the skin.
  • •Neck: Measure just below the larynx (Adams apple). Keep the tape horizontal, looking straight ahead.
This calculator uses the U.S. Navy body fat formula and a BMI-based estimate. Results are approximations. All calculations happen in your browser.

How to Use This Tool

  1. 1

    Select gender and units

    Choose male or female and select metric (cm/kg) or imperial (in/lbs) units.

  2. 2

    Enter your measurements

    Input your age, height, weight, waist circumference, and neck circumference. Women also need hip circumference.

  3. 3

    View your results

    See your estimated body fat percentage, fat mass, lean body mass, and body composition category.

  4. 4

    Check the categories

    Compare your result against standard body fat categories for your gender to understand where you fall.

Frequently Asked Questions

How accurate is the U.S. Navy method?
The U.S. Navy method is generally accurate within 1-3% of DEXA scan results for most people. It is one of the most widely validated tape-measure methods available.
What is a healthy body fat percentage?
For men, 14-17% is considered fit and 18-24% is average. For women, 21-24% is fit and 25-31% is average. Athletes typically have lower body fat percentages.
Why do I need to measure my neck?
The Navy formula uses the relationship between waist and neck circumferences to estimate body fat. The neck measurement helps account for differences in body frame and muscle mass.
Is my data secure?
Yes. All calculations happen entirely in your browser using JavaScript. No personal measurements are sent to any server.