Body Fat Calculator: How It Works and How to Use It
Estimate your body fat percentage using the US Navy tape-measure method from your height, neck, waist, and hip measurements.
Like every tool on UltimateTools, it runs instantly in your browser, updates as you type, and doesn't require an account or sign-up to use.
What it calculates
Estimate your body fat percentage from a few measurements.
Whether you think of it as a "body fat calculator" tool, a "body fat percentage calculator" tool, or simply the Body Fat Calculator, this page covers the same calculation.
You can find it at any time on the Body Fat Calculator page, where the calculator sits above a full explanation of the method it uses.
Tips for an accurate result
Use consistent measurement conditions each time (same scale, same time of day) so results are comparable over time.
Be honest with activity-level inputs; overestimating how active you are is one of the most common ways these calculators end up wrong.
These estimates are general-population formulas, not medical advice — check with a professional for anything that affects a health decision.
If a result seems unusual, re-enter your inputs carefully before assuming something is medically wrong — a typo is far more common than an anomaly.
Related tools worth trying
If you found the Body Fat Calculator useful, BMI Calculator, Ideal Weight Calculator, Calorie Calculator cover closely related ground and are worth a look next.