Body Fat Calculator — Estimate Your Body Fat Percentage
Use this free body fat calculator to estimate your body fat percentage based on your body measurements. Using the US Navy Method — one of the most accurate measurement based formulas available — enter your height, waist, neck and hip measurements for an instant result with category rating and body composition breakdown.
Body Fat Calculator
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How to Use the Body Fat Calculator
Select your gender and choose metric or imperial units. Enter your age, height, waist circumference at the navel, neck circumference below the larynx and hip circumference at the widest point if female. Click Calculate for your body fat percentage and category.
How to Take Accurate Measurements
Waist — measure at the navel level. Keep the tape horizontal and don’t suck in your stomach. Measure first thing in the morning for consistency.
Neck — measure just below the larynx (Adam’s apple). Keep the tape horizontal and look straight ahead.
Hip (women only) — measure at the widest point of your hips and buttocks. Keep the tape horizontal.
Consistency matters more than precision — always measure at the same time of day and in the same position.
How Is Body Fat Calculated?
This calculator uses the US Navy Method developed by Hodgdon and Beckett in 1984. It uses circumference measurements to estimate body fat percentage using a logarithmic formula:
Men: Body Fat % = 495 ÷ (1.0324 − 0.19077 × log(waist − neck) + 0.15456 × log(height)) − 450
Women: Body Fat % = 495 ÷ (1.29579 − 0.35004 × log(waist + hip − neck) + 0.22100 × log(height)) − 450
Body Fat Percentage Categories
Men:
Essential Fat: 2–5% — minimum fat for body function
Athletes: 6–13% — competitive athletes
Fitness: 14–17% — lean and fit
Average: 18–24% — typical healthy adult
Obese: 25%+ — excess body fat
Women:
Essential Fat: 10–13% — minimum fat for body function
Athletes: 14–20% — competitive athletes
Fitness: 21–24% — lean and fit
Average: 25–31% — typical healthy adult
Obese: 32%+ — excess body fat
Women naturally carry more essential fat than men due to hormonal and reproductive differences.
Body Fat vs BMI — What's the Difference?
BMI (Body Mass Index) uses only height and weight — it cannot distinguish between fat and muscle. A muscular person can have a high BMI while having low body fat. Body fat percentage directly measures the proportion of fat in your body making it a more accurate indicator of health and fitness than BMI alone.
FAQs
How accurate is the US Navy Method?
The US Navy Method has an accuracy of approximately ±3-4% compared to gold standard methods like DEXA scanning. It’s one of the most accurate measurement based methods available without specialist equipment.
What is a healthy body fat percentage?
For men 14-17% is considered fitness level and 18-24% is average healthy. For women 21-24% is fitness level and 25-31% is average healthy. These ranges vary by age — older adults naturally carry slightly more body fat.
How is body fat different from BMI?
BMI uses height and weight only and cannot distinguish fat from muscle. Body fat percentage directly measures how much of your body is fat making it a more useful health marker especially for active or muscular individuals.
How can I reduce body fat percentage?
A calorie deficit combined with resistance training is the most effective approach. The deficit burns fat while resistance training preserves and builds muscle — improving body composition even when total weight loss is modest.
What is essential body fat?
Essential fat is the minimum fat required for basic physiological functions — protecting organs, regulating hormones and supporting the nervous system. For men this is 2-5% and for women 10-13%. Going below essential fat levels is dangerous.
Is this calculator free?
Yes completely free with no sign-up needed.