Body Fat Percentage Calculator
Estimate your body fat percentage using the US Navy circumference method — no calipers or equipment needed. Enter a few simple body measurements to see where you fall on the body fat scale, what your category means, and what to do next.
Enter your measurements
Use the US Navy method — measure at the widest point of each body part. Take measurements in the morning before eating for most consistent results.
About the US Navy method
Uses height, waist, neck, and hip (women) circumferences. Accuracy is ±3–4% compared to DEXA scanning. More practical than calipers for self-measurement.
Measurement tips
Use a flexible tape measure. Keep it parallel to the floor. Measure 3 times and use the average. Don't pull the tape tight — just snug against skin.
What is body fat percentage?
Body fat percentage is the proportion of your total body weight that is made up of fat. The rest is lean mass — muscle, bone, organs, water, and connective tissue.
Unlike BMI, which only uses height and weight, body fat percentage distinguishes between fat and muscle. Two people with the same BMI can have very different body compositions — a muscular athlete and a sedentary person may both show "overweight" on BMI but have very different body fat levels.
US Navy method formula
This calculator uses the US Navy circumference method — one of the most practical for self-measurement:
Body fat categories by sex
Women naturally carry more body fat than men due to hormonal and reproductive physiology. The "essential fat" minimum for women is higher because it is required for normal hormonal function.
How to take accurate measurements
- Height: Stand straight against a wall, no shoes. Measure from floor to top of head.
- Waist: Measure at navel level (belly button), relaxed — not sucked in. Keep tape parallel to floor.
- Neck: Measure below the larynx (Adam's apple), with the tape slightly downward at the front.
- Hip (women): Measure at the widest point of the hips and buttocks, tape parallel to floor.
- Take each measurement 3 times and use the average for best accuracy.
Frequently asked questions
How accurate is the US Navy body fat method?
The US Navy method has an accuracy of approximately ±3–4% compared to DEXA scanning, which is considered the gold standard. It is less accurate than calipers done by a professional, but more practical and consistent for self-tracking at home.
What is a healthy body fat percentage?
For men, the fit range is generally 14–17%. For women, 21–24%. Athletes typically fall in the 6–13% (men) and 14–20% (women) ranges. Essential fat minimums are 2–5% for men and 10–13% for women — going below these is dangerous.
Why do I need hip measurements as a woman?
Women naturally carry more fat in the hip and gluteal region. The US Navy formula for women includes hip circumference to account for this distribution difference, which improves estimation accuracy compared to using waist and neck alone.
How is body fat percentage different from BMI?
BMI uses only height and weight — it cannot distinguish fat from muscle. Body fat percentage directly estimates how much of your weight is fat. A muscular person can have a high BMI but low body fat, while a sedentary person can have a normal BMI but high body fat ("skinny fat").
How often should I measure body fat?
Monthly measurements are sufficient for most people. More frequent is not more useful because body composition changes slowly. Always measure at the same time of day (morning is best), under the same conditions, to get comparable results.
Related health calculators
These tools pair naturally with body fat percentage for a complete body composition picture.
Disclaimer
This body fat calculator uses the US Navy circumference method and provides estimates with a margin of error of approximately ±3–4%. Results are for informational and screening purposes only and do not constitute medical advice or diagnosis. Consult a healthcare professional for clinical body composition assessment.