Body Fat Calculator
Estimate body fat percentage using the U.S. Navy circumference method. Supports metric and imperial units. Informational only.
Informational estimate only (not medical advice). Privacy: runs locally in your browser. No inputs are stored or sent to a server.
How it works
This tool uses the U.S. Navy body fat method (circumference-based). Measurements should be taken with a flexible tape. Keep the tape level and snug (not compressing the skin).
The method uses logarithms, so relative measurement accuracy matters. Measuring consistently (same time of day, same tape tension) helps when tracking over time.
- Male inputs: height, neck, waist
- Female inputs: height, neck, waist, hip
Examples
- Male: Height 175 cm, Neck 38 cm, Waist 85 cm → estimate body fat %
- Female: Height 165 cm, Neck 34 cm, Waist 75 cm, Hip 95 cm → estimate body fat %
FAQ
- How does this body fat calculator work?
It estimates body fat percentage using the U.S. Navy method, which uses circumference measurements and height (and includes neck/waist, plus hip for females).
- Is this accurate?
It’s a practical estimate, but not a medical-grade measurement. Accuracy depends on measurement technique and individual body shape.
- Who is this calculator for?
It’s intended for adults. Body fat estimation methods and healthy ranges differ for children and teens.
- Do I need to measure in a specific way?
Use a flexible tape measure, keep it level, and measure snugly without compressing the skin. Measure in consistent conditions for better comparisons over time.
- Is my data stored?
No. All calculations run locally in your browser. Inputs are not sent to a server.