Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy Method — free online body fat calculator for men and women. Enter height, neck, and waist/abdomen measu...
To estimate body fat percentage, choose gender and units, then enter height, neck and abdomen (men) or waist and hip (women); the U.S. Navy formula gives an estimate, not medical advice.
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Body Fat Calculator. Estimate your body fat percentage using the U.S. Navy Method — free online body fat calculator for men and women. Enter height, neck, and waist/abdomen measurements for an instant result.
Estimate your body fat percentage instantly with our free online body fat calculator. Using the U.S.
Navy Method — one of the most widely used and accessible approaches for estimating body composition — simply enter your height, neck, and abdomen (men) or waist and hip (women) measurements to get your body fat percentage and category in seconds.
Our navy body fat calculator supports both metric (cm) and imperial (in) units and runs entirely in your browser — no personal measurements are ever sent to a server. The U.S.
Navy formula is the same method used by military fitness assessors to evaluate body composition. Results are classified into categories: Essential Fat, Athletes, Fitness, Average, or Obese.
Pair with our BMI Calculator or BMR Calculator for a fuller health picture.
Frequently asked questions
How do I calculate my body fat percentage?
Select Metric (cm) or Imperial (in) and Male or Female. Men enter Height, Neck and Abdomen; women enter Height, Neck, Waist and Hip. The estimated body fat percentage and its category appear instantly. It is an estimate for information only, not medical advice.
How should I take the measurements?
Use a flexible tape measure held snug but not tight. In the U.S. Navy method, the neck is measured just below the larynx, men measure the abdomen around the navel, and women measure the waist at its narrowest point and the hips at their widest. Use a dot, not a comma, for decimals.
What formula does this navy body fat calculator use?
The U.S. Navy circumference formulas with measurements in inches. Men: 86.010 x log10(abdomen - neck) - 70.041 x log10(height) + 36.76. Women: 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387. Metric entries are converted to inches first, and the result is rounded to one decimal.
What do the body fat categories mean?
Men: below 6% Essential Fat, 6 to 13.9% Athletes, 14 to 17.9% Fitness, 18 to 24.9% Average, 25% and above Obese. Women: below 14% Essential Fat, 14 to 20.9% Athletes, 21 to 24.9% Fitness, 25 to 31.9% Average, 32% and above Obese.
Why is no result shown?
Every field needs a number. For men the abdomen must be larger than the neck, and for women the waist plus hip must be larger than the neck; otherwise the formula cannot be calculated and the result box stays hidden.
How accurate is the U.S. Navy body fat method?
It estimates body fat from body shape, so results can differ from clinical methods such as DEXA scans or hydrostatic weighing, especially for very muscular or very lean people. Use it to track changes over time and ask a healthcare provider for a full body composition assessment.
How to use this online tool
Body Fat Calculator is designed for fast browser workflows when you need to format, validate, convert, decode, encode, generate, or inspect data without opening a heavy desktop app. Start with the input field or visible options, review the result, then copy or download the output for the next step.
Private processing in your browser
Body Fat Calculator keeps the normal processing step local in your browser. That is useful for code snippets, tokens, documents, configuration values, text samples, and other material that should not be sent to a remote service unless you explicitly choose to share it.
When this tool is useful
Use Body Fat Calculator for repeatable developer tasks, technical documentation, QA checks, quick conversions, debugging, content cleanup, and internal team workflows. The page focuses on clear inputs, immediate feedback, and output that is easy to reuse in code, reports, tickets, emails, or notes.
Practical tips
Before copying the final result, check important details such as spacing, casing, filenames, encoding, token structure, line breaks, or output format. Small checks prevent mistakes when the result is reused in source code, API requests, documentation, spreadsheets, or shared files.