Estimate your body fat percentage with the US Navy method.
What is body fat percentage? Body fat percentage is the share of your total body weight that is fat tissue, as opposed to muscle, bone, and water. It is a better fitness indicator than weight alone โ healthy ranges are roughly 10โ20% for men and 18โ28% for women.
Use a flexible tape measure. Waist at the navel, neck just below the Adam's apple, hip at the widest point.
Estimated body fat
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Category
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Fat mass
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Lean mass
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US Navy method โ a good estimate, not a medical measurement.
Tip: calculate first โ your result is included when you share.
๐ Related guide:How to Calculate Ideal Weight for Your Height โ your healthy weight is a range, not one number: the BMI range formula and the Devine formula, with worked examples.
How to Use the Body Fat Calculator
Body Mass Index tells you about weight, but it can't tell muscle from fat. Body fat percentage is the more useful number: two people with the same BMI can have very different health profiles depending on how much of their weight is fat. This calculator uses the US Navy method, developed from circumference measurements of military personnel.
To use it, select your gender, enter your height, weight, neck and waist measurements (plus hip for women), then press Calculate Body Fat. You'll get your estimated body fat percentage, a category โ essential, athletes, fitness, average or obese โ and a split of fat mass versus lean mass.
The formulas are: for men, 86.010 ร log10(waist โ neck) โ 70.041 ร log10(height) + 36.76; for women, 163.205 ร log10(waist + hip โ neck) โ 97.684 ร log10(height) โ 78.387. Measurements go in as inches internally, so enter centimetres and the calculator converts automatically.
Typical healthy ranges are about 10โ20% for men and 18โ28% for women, with athletes lower. This is an estimate โ DEXA scans and hydrostatic weighing are more accurate but expensive. Measure consistently (same time of day, same tape position) and track the trend rather than obsessing over a single reading. Pair it with our BMI Calculator and Calorie Calculator for a full fitness plan.
Frequently Asked Questions
What is a healthy body fat percentage?
For men, roughly 10โ20% is considered healthy (athletes 6โ13%); for women, roughly 18โ28% (athletes 14โ20%). Essential fat โ the minimum for health โ is about 2โ5% for men and 10โ13% for women.
How accurate is the US Navy body fat method?
It's a solid field estimate, usually within 3โ4% of lab methods like DEXA when measurements are taken carefully. Consistent technique matters more than the formula โ always measure the same way.
Why does the formula need neck and waist measurements?
Neck size correlates with overall frame/muscle, while waist reflects abdominal fat. The formula uses the difference between them (plus hip for women) to estimate fatness without a scale-only weight input.
Is body fat percentage better than BMI?
For fitness tracking, yes โ BMI can't distinguish muscle from fat, so muscular people score as 'overweight'. Body fat percentage directly measures what you want to change.
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