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If you have a soft tape, use the Navy inputs for the best estimate. If not, the BMI estimate gives a quick fallback.
This tool estimates body fat percentage two ways so you can pick what fits your situation. The U.S. Navy method uses a few tape measurements with your height to estimate body fat. It’s quick, repeatable, and usually tracks change well when you measure the same way each time. If you don’t have a tape handy, the BMI-based estimate gives a rough number using BMI, age, and sex. It’s less personal than tape, but it’s better than guessing.
Your results also break weight into lean mass and fat mass, and show an ideal weight for a target body fat while keeping lean mass constant. That last part is an assumption. In real life, training, protein intake, sleep, and genetics can nudge lean mass up or down. Treat these numbers as markers, not verdicts.
For the best consistency, measure in the morning, same conditions, and in the same spots (neck, waist, and hips for women). Keep the tape level and snug without compressing the skin. If your Navy and BMI numbers don’t match, pick one method and stick with it over time. Trends beat single snapshots. For medical decisions, talk with a clinician.
You might also like: BMI, BMR & Calories, Macro Calculator.
Use the Navy method when you have good tape measurements. The BMI estimate is a quick fallback when you don’t.
Snug but not compressing the skin. Keep the tape level and measure at the same spots each time.
That’s normal. Pick one method and track with it over time for consistency. The Navy method usually reflects changes better.
There isn’t one number for everyone. Many healthy targets are ~10–18% for men and ~18–25% for women, depending on goals and context.
It’s an estimate based on keeping lean mass constant. Training, diet, and genetics can shift lean mass as you change body fat.