Body Fat Percentage Calculator
Body fat percentage measures the proportion of fat tissue in your body relative to your total weight. Unlike BMI, which only considers height and weight, body fat percentage provides a more accurate picture of body composition by distinguishing between fat mass and lean mass such as muscle, bone, and organs.
Knowing your body fat percentage helps you set realistic fitness goals and track meaningful progress. Essential fat levels differ between men and women — men typically need 2–5% essential fat while women need 10–13%. Athletes generally maintain 6–13% (men) or 14–20% (women), while a healthy fitness range is 14–17% (men) or 21–24% (women). Methods for estimating body fat include skinfold calipers, bioelectrical impedance, and Navy method calculations using body measurements.
How it works
The U.S. Navy method estimates body fat using circumference measurements: for men, BF% = 86.010 × log10(abdomen − neck) − 70.041 × log10(height) + 36.76; for women, BF% = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387.
Use cases
- Tracking body composition changes during fitness programs
- Setting personalized fat loss or muscle gain targets
- Monitoring health risks associated with excess body fat
- Comparing progress beyond what the scale shows alone
Frequently asked questions
How can I calculate body fat percentage at home?
The U.S. Navy method only requires a tape measure. Men measure neck and abdomen circumference; women measure neck, waist, and hip. The calculator applies logarithmic formulas — for men, BF% = 86.010 × log10(abdomen − neck) − 70.041 × log10(height) + 36.76 — to estimate your body fat percentage without any special equipment.
What is a healthy body fat percentage?
A healthy fitness range is about 14–17% for men and 21–24% for women. Athletes typically sit at 6–13% (men) or 14–20% (women), while essential fat — the minimum needed for basic physiological function — is 2–5% for men and 10–13% for women. Going below essential fat levels is dangerous, so discuss aggressive fat loss goals with a healthcare professional.
How accurate is the Navy method for body fat?
It is an estimate based on circumference measurements, so results can differ by a few percentage points from clinical methods like DEXA scans or hydrostatic weighing. Its main strength is consistency: measured the same way at the same time of day, it tracks changes in body composition reliably over time. Measurement technique matters — keep the tape level and snug but not compressing the skin.
What is the difference between BMI and body fat percentage?
BMI only uses height and weight, so it cannot distinguish muscle from fat — a muscular athlete can register as overweight. Body fat percentage measures the actual proportion of fat tissue relative to total weight, giving a truer picture of body composition. That is why two people with identical BMI can have very different body fat levels.
Why are the measurements different for men and women?
Men and women store fat in different body regions, so the Navy formulas use different measurement sites. Men use abdomen and neck circumference, while women use waist, hip, and neck, because women typically carry more fat around the hips. The female formula also reflects higher essential fat requirements (10–13% versus 2–5% for men).