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Estimate body fat % using circumference measurements.
Fitness
⚖️ The US Navy method estimates body fat from tape measurements; the BMI method (Deurenberg formula) estimates it from your BMI, age, and sex. Both are less accurate than DEXA scans but practical at-home estimates.
This calculator estimates body fat percentage using the US Navy method, which uses circumference measurements of your neck, waist, and (for women) hips. It's a practical at-home alternative to expensive body composition scans.
BMI cannot distinguish muscle from fat. A muscular athlete and an overweight person can have the same BMI but very different body fat percentages and health risks. Body fat is the more meaningful metric — though harder to measure precisely.
Disclaimer: This tool is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Results are estimates and should be discussed with a qualified healthcare provider before making health-related decisions.
The Body Fat Calculator lets you figure out body fat calculatorinstantly, without reaching for a spreadsheet or doing the math by hand. Whether you're planning a budget, checking a loan, or working through homework, the tool applies the correct formula behind the scenes and shows the result the moment you enter your numbers.
Unlike a static chart or table, this calculator adapts to your exact inputs. You can adjust any value and see the outcome update in real time, which makes it easy to compare scenarios — for example, "what if the rate were 1% lower?" or "what if I paid an extra $50 a month?"
Common uses: people reach for this tool when they need to find a body fat calculator navy method, body fat by waist and neck, us navy body fat formula, or body fat percentage by measurements.
Browser-based tools like this one have a few real advantages over installed software or manual methods:
The Body Fat Calculator is based on the following formula:
BF% (US Navy) from height, neck, waist (and hip for women)
Variables: BF% = Estimated body-fat percentage height = Height (cm, or inches in the imperial variant) neck = Neck circumference below the larynx (cm) waist = Waist circumference at the navel (cm) hip = Hip circumference at the widest point (women only)
The U.S. Navy method estimates body-fat percentage from circumference measurements. It is convenient and free but less precise than clinical methods like DEXA or hydrostatic weighing.
Worked example: Step 1: A man 180 cm tall, neck 38 cm, waist 85 cm; waist − neck = 47. Step 2: log10(47) ≈ 1.672; log10(180) ≈ 2.255. Step 3: Denominator = 1.0324 − 0.19077 × 1.672 + 0.15456 × 2.255 ≈ 1.0324 − 0.319 + 0.349 = 1.062. Step 4: BF% = 495 ÷ 1.062 − 450 ≈ 466.1 − 450 = 16.1. Result: estimated body fat about 16.1%, in the fitness range for men.
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