Body Fat % Calculator

How to Estimate Body Fat at Home

This calculator uses the US Navy circumference method, which estimates body fat from neck, waist, and hip (women only) measurements. While not as accurate as DEXA scans or hydrostatic weighing, it's free, requires only a tape measure, and has reasonable accuracy (±3–4%) for most people when measurements are taken consistently.

Body fat categories: Essential fat 2–5% (M) / 10–13% (F) · Athletes 6–13% (M) / 14–20% (F) · Fitness 14–17% (M) / 21–24% (F) · Average 18–24% (M) / 25–31% (F) · Obese 25%+ (M) / 32%+ (F).

Frequently Asked Questions

• How accurate is the Navy body fat method?
  The Navy method typically has an error of ±3–4% compared to DEXA. It's more accurate than BMI for assessing body composition and works well for tracking changes over time even if the absolute number is slightly off.
• Where exactly do I measure waist circumference?
  For the Navy method, measure at the narrowest point (usually at or slightly above the navel for men). Women measure at the navel. Take the measurement while exhaling normally — don't suck in. Take 2–3 readings and average them.
• What is a healthy body fat percentage?
  Healthy ranges differ by sex and age. For men, 10–20% is considered fit to healthy; athletes often fall in the 6–13% range. For women, 18–28% is healthy; female athletes typically fall between 14–20%. Above 25% (men) or 32% (women) is generally classified as obese by body fat standards, even if BMI appears normal.
• How is the US Navy body fat method calculated?
  The Navy method uses circumference measurements to estimate body fat. For men, it uses neck and waist measurements. For women, it uses neck, waist, and hip measurements. These values are plugged into a logarithmic formula developed by the US Navy. It's considered reasonably accurate (within 3–4%) compared to more complex methods like DEXA scans or hydrostatic weighing.

Estimating Body Fat with the Navy Method

Body-fat percentage tells you something BMI can't: how much of your weight is fat versus lean tissue like muscle and bone. This calculator uses the U.S. Navy circumference method, which estimates body fat from simple tape measurements — neck and waist for everyone, plus hips for women — along with height. It's far more accessible than a lab scan and, when measurements are taken carefully, reasonably accurate for tracking changes over time. Because it focuses on where you carry fat, it gives a more meaningful read on body composition than weight alone.

How to Measure Accurately

Consistency is what makes the result trustworthy. Measure with a flexible tape pulled snug but not compressing the skin, ideally first thing in the morning. For the neck, measure just below the larynx; for the waist, measure at the navel for men and at the narrowest point for women; for the hips, measure at the widest point. Take each measurement two or three times and average them. Small differences in tape placement can shift the estimate by a percentage point or more, so measuring the same way each time matters more than chasing a perfect single reading.

What the Numbers Mean

Healthy body-fat ranges differ by sex because women naturally carry more essential fat. General guidelines put athletic men around 6–17% and women around 14–24%, with "fitness" and "acceptable" ranges somewhat higher, and essential minimums below which health suffers. Rather than fixating on a single target, use the calculator to track the trend: a steady decline over weeks during a fat-loss phase, or stability while you build muscle, tells you more than any one measurement. Pair it with how your clothes fit and your performance in the gym for a rounded picture.

• How accurate is the Navy body-fat method?
  It's an estimate, typically within a few percentage points of more advanced methods when measurements are taken carefully. Its real strength is tracking change consistently over time rather than a single precise reading.
• What's a healthy body-fat percentage?
  It varies by sex and age. Broadly, fit ranges fall around 10–20% for men and 18–28% for women, with athletes lower. Going too low is unhealthy because some fat is essential.
• Why is body fat better than BMI?
  Body fat distinguishes fat from muscle, so it doesn't misclassify muscular people the way BMI can. It gives a clearer view of body composition and health risk.