How to use this calculator
- 1
Measure your waist
Take a tape-measure reading at the navel for men, or at the narrowest point for women. Stand relaxed; do not suck in.
- 2
Measure your neck
Just below the larynx, with the tape level around the neck.
- 3
Measure your hip (women only)
At the widest point of the hips with feet together.
- 4
Enter measurements
Input height, weight, and circumferences. The calculator returns body fat %, lean body mass, and a health-range classification.
What this calculator gives you
- U.S. Navy method (tape measurements only)
- BMI-based estimate as a quick fallback
- Skinfold caliper input (3-site Jackson-Pollock)
- Lean body mass and fat mass breakdown
- Visual body-fat range charts for men and women
Formulas used
U.S. Navy (men)
%BF = 86.010×log10(waist − neck) − 70.041×log10(height) + 36.76
Best for: Field measurement with tape only
U.S. Navy (women)
%BF = 163.205×log10(waist + hip − neck) − 97.684×log10(height) − 78.387
Best for: Field measurement with tape only
Jackson-Pollock 3-site
Sum of three skinfolds → body density → %BF
Best for: More accurate when calipers and a trained measurer are available
Frequently asked questions
How accurate is the U.S. Navy body fat formula?+
Compared to DEXA, the U.S. Navy method has roughly ±3–4% error for most people. It is more accurate than BMI-based estimates and accessible without specialized equipment.
What is a healthy body fat percentage?+
Men: 10–20% is the healthy range; 6–13% for athletes. Women: 18–28% is healthy; 14–20% for athletes. Below the athlete range, hormonal and immune function can suffer.
How can I lower my body fat percentage?+
Combine a moderate calorie deficit (15–20% below TDEE), high protein (1 g/lb), and resistance training 3–4×/week. Expect 0.5–1% body fat reduction per month at a sustainable pace.
Want the full guide?
The complete article goes deeper into the science, with charts, comparisons, and practical examples.
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