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Health & Fitness

Body Fat Percentage Estimator

Estimate body fat percentage with the US Navy circumference method from height, neck, waist and (for women) hip measurements.

Your inputs

Results

Estimated body fat

17%

Fat mass
11.9 kg
Lean mass
58.1 kg

≈Estimate based on the stated model and assumptions

Notes for this result

  • This is a population-level estimate for adults, not a diagnosis. Discuss health decisions with a qualified professional.
  • US Navy circumference method (Hodgdon & Beckett, 1984). Typical error versus lab methods is a few percentage points; measure consistently for tracking.

Inputs are never added to links for financial, salary or health calculators.

What this calculator does

The Navy method estimates body fat from a few tape measurements. It is practical for tracking change over time.

Formula and method

Men: %BF = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76 Women: %BF = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387 (inches)

Worked example

Calculated by this tool with its default inputs:

Inputs

  • Units for lengths: Centimetres
  • Sex (used by the formula): Male
  • Height: 175 cm / in (see Units)
  • Neck circumference (below the larynx): 38 cm / in (see Units)
  • Waist circumference (men: at navel; women: narrowest point): 85 cm / in (see Units)
  • Body weight (optional, for fat mass): 70 kg or lb

Results

  • Estimated body fat: 17%
  • Fat mass: 11.9 kg
  • Lean mass: 58.1 kg

How to read the results

Expect a typical error of a few percentage points against laboratory methods; consistency of measurement matters most.

Assumptions and limitations

  • Measure the waist at the navel (men) or narrowest point (women), and the neck just below the larynx.
  • An estimate for healthy adults, not a diagnosis or medical advice. Consult a qualified health professional about your personal situation.

Health results are general estimates for adults and do not replace medical advice, diagnosis or treatment. Speak to a qualified health professional about your personal situation, especially during pregnancy or if you have a medical condition.

Questions

Is this as accurate as a DEXA scan?

No. It is a convenient estimate; laboratory methods are more accurate.

Sources

  • Hodgdon JA, Beckett MB. Prediction of percent body fat for U.S. Navy men and women from body circumferences and height. Naval Health Research Center, 1984.

Methodology and verification

Result type
Estimate based on the stated model and assumptions
Formula version
1.0
Automated verification
3 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
Editorial review
Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.

Privacy

Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Because this calculator can involve personal financial or health details, your inputs are never added to share links or saved to history. Privacy policy