📏 Body Fat Percentage Estimator

Three methods. One number. Your choice. All calculations run in your browser — we never see your data.

Navy Method (Circumference)

Uses neck and waist measurements. Fast, no equipment beyond a tape measure.

How It Works

This estimator combines three validated methods to give you a range of body fat percentages. The Navy Method uses neck and waist circumference — fast, free, and requires only a tape measure. The YMCA Method simplifies further with just weight and waist. The Jackson-Pollock Skinfold method uses caliper measurements at 3 or 7 sites and is the most accurate home option when performed correctly. Each method has known error margins (shown in your results). We recommend using 2-3 methods and comparing the range rather than trusting any single number.

Navy Method
Error: ±4-6%
Needs: Tape measure
YMCA Method
Error: ±5-8%
Needs: Scale + tape
3-Site Skinfold
Error: ±4-6%
Needs: Calipers + skill
7-Site Skinfold
Error: ±3-5%
Needs: Calipers + experience

Tip: Measure at the same time of day, under the same conditions. Hydration and meal timing can shift readings by 1-3%.

📊 Saved Results

Compare your measurements over time. Data is stored locally in your browser.

No saved results yet. Calculate and save to start tracking.

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📝 Skinfold Tracker

Log your skinfold measurements over time.