Body Fat Percentage Calculator
Measure at navel level
Measure at widest point. Used in female formula; optional for males.
This calculator provides estimates for educational purposes only and is not medical advice. The US Navy method is accurate within 3-4% for most people. Consult a healthcare provider for precise body composition analysis.
What is body fat percentage?
Body fat percentage tells you how much of your total weight is fat. Unlike BMI, which only considers weight and height, body fat percentage distinguishes between fat mass and lean mass (muscle, bone, water). This makes it a more accurate indicator of health and fitness.
The US Navy method
Developed by the US Navy for fitness assessments, this method uses simple tape measurements — neck, waist, and hip circumference — combined with your height to estimate body fat. The formula uses logarithmic calculations based on where your body stores fat relative to your frame size.
Body fat categories
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2–5% | 10–13%* |
| Athlete | 6–13% | 14–20%* |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
* These low bands describe where some competitive athletes sit in season, usually at a cost - they are not targets. For women, sustained body fat below roughly 18-20% is where menstrual disruption becomes common. If your periods get irregular or stop while leaning out, that is a medical issue to raise with a doctor, not a macro problem to push through.
Want to understand your overall weight status? Try our BMI Calculator. To find your daily calorie needs based on your body composition, use the Daily Calorie Intake Calculator.
Frequently asked questions
What is body fat percentage?
Body fat percentage is the proportion of your total body weight that is fat tissue. It includes both essential fat (needed for basic functions like hormone production and organ protection) and storage fat (energy reserves). Unlike BMI, body fat percentage directly measures fat rather than just weight relative to height.
How does the US Navy method work?
The US Navy body fat method uses circumference measurements — neck, waist, and hip (for women) — along with your height. These measurements are plugged into a logarithmic formula developed by the US Navy for fitness assessments. It estimates body fat percentage without expensive equipment like DEXA scans or calipers.
What is a healthy body fat percentage?
Healthy ranges differ by gender. For men: 14-17% is fitness level, 18-24% is average. For women: 21-24% is fitness level, 25-31% is average. Athletes typically have lower body fat (6-13% for men, 14-20% for women). Essential fat — the minimum needed for health — is 2-5% for men and 10-13% for women.
How accurate is the US Navy method?
The US Navy method is accurate within 3-4% for most people when measurements are taken correctly. It is less accurate for very muscular individuals or those with unusual body proportions. For more precise results, consider DEXA scanning or hydrostatic weighing. However, the Navy method is excellent for tracking changes over time.
What is the difference between body fat percentage and BMI?
BMI (Body Mass Index) uses only weight and height to estimate whether you are underweight, normal, or overweight. It cannot distinguish between muscle and fat — a muscular athlete may have a "high" BMI but low body fat. Body fat percentage directly estimates how much of your weight is fat, giving a more accurate picture of body composition.
Formulas and scientific references US Navy circumference method (Hodgdon and Beckett, 1984): body density estimated from height plus neck, waist and, for women, hip circumference, then converted to body fat percentage.
Sources
- Hodgdon JA, Beckett MB. Prediction of percent body fat from body circumferences and height (the US Navy method). Naval Health Research Center, San Diego, 1984
This calculator gives a general educational estimate, not medical or individualized nutrition advice. Prediction equations are wrong by more than 10% in roughly 1 in 3 people.