📏 Body Fat Calculator

What is Body Fat Calculator?

The Body Fat Calculator estimates body fat percentage from simple circumference measurements using the US Navy method. Enter your neck, waist and height (plus hips for women), choose metric or imperial units, and the tool returns an estimated body fat percentage with a plain-language fitness category. It is a practical, no-cost way to track body-composition trends over time from home. All measurements are processed locally and never uploaded.

How to Use Body Fat Calculator

1. Measure your neck, waist and height (and hips for women) with a tape measure
2. Enter the values and pick metric or imperial
3. Read your estimated body fat percentage and category

Why Use Our Body Fat Calculator?

• Estimate body fat from tape measurements — no special equipment
• Metric and imperial unit support with live switching
• Clear category labels from essential fat to obese
• Private, in-browser math with no account

Common Use Cases

• Tracking body composition trends during a fat-loss phase
• Estimating body fat when skinfold calipers are unavailable
• Getting a quick baseline before starting a fitness program

Frequently Asked Questions

• How accurate is the US Navy method?▾
  Circumference-based estimates are usually within about three percent of more advanced methods when measurements are consistent, which makes them useful for tracking change over time.
• Where exactly should I measure?▾
  Neck: just below the larynx. Waist: at the navel for men and the narrowest point for women. Hips (women only): the widest point around the buttocks.
• Why do I need my height and sex?▾
  The Navy formula scales differently for men and women and uses height in its logarithm terms, so those fields are required for the estimate.