Health calculator

Body Fat Percentage Calculator

Estimate body fat percentage with the Navy tape method or a quick BMI-based comparison using height, weight, sex, and body measurements.

Measurement guide

How to measure body fat at home

For the tape method, measure height, neck, waist, and hip circumference with the same unit system. Keep the tape level, snug, and flat against the skin without pulling it tight.

For men, the Navy equation uses height, neck, and waist. For women, it uses height, neck, waist, and hip. Take each measurement in a relaxed standing posture and repeat if the tape moved or twisted.

The BMI estimate needs only height, weight, age, and sex. It is faster, but it is a rough comparison because BMI does not separate fat mass from muscle, bone, or water.

Which method should I use?

  • Use the Navy tape method when you can measure neck, waist, and hip consistently.
  • Use the BMI estimate for a quick check when you only know height and weight.
  • Use DEXA, calipers, BIA, or a clinician if accuracy matters for health decisions.

Related calculators

BMI CalculatorWaist-to-Hip RatioLean Body Mass
FormulaMen: 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76; Women: 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387

Formula

Navy body fat estimate

Body-fat formulas are screening estimates and can differ from DEXA, calipers, smart scales, and clinician measurements. They do not diagnose health risk.

Men: 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76; Women: 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387

For a man, enter height, neck, and waist circumference; for a woman, hip circumference is included too.

SourcesThis calculator includes source notes, assumptions, and exclusions so the result is easier to verify before use.

Sources and assumptions

Source notes

This calculator includes source notes, assumptions, and exclusions so the result is easier to verify before use.

Effective year
Current rules
Last verified
2026-06-18

Body-fat formulas are screening estimates and can differ from DEXA, calipers, smart scales, and clinician measurements. They do not diagnose health risk.

Official and reference sources

Assumptions

  • The Navy tape method uses height, neck, waist, and hip circumference inputs converted to inches before applying the formula.
  • The BMI comparison uses the adult BMI, age, and sex equation and is shown as a secondary estimate.
  • Measurements should be taken consistently with a flexible tape and relaxed posture.

Not included

  • DEXA, hydrostatic weighing, air displacement, skinfold calipers, bioelectrical impedance, pregnancy, children, and clinical diagnosis.
FAQ6 common questions for this calculator.

FAQs

How do I measure body fat at home?+

Use a flexible tape and measure height, neck, waist, and hip when needed. Keep the tape level and snug without compressing the skin, then compare the result with other methods if accuracy matters.

Is the Navy body fat calculator exact?+

No. It is a circumference-based estimate. It can be useful for tracking a consistent method over time, but it is not the same as a DEXA scan, caliper assessment, or clinical body-composition test.

Why does the calculator show a BMI comparison?+

BMI is easy to calculate from height and weight, so it gives a quick comparison. It does not measure body composition directly, so the tape-method estimate is the primary result when measurements are available.

How does the Body Fat Percentage Calculator calculate the result?+

It uses the Navy body fat estimate: Men: 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76; Women: 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387. For a man, enter height, neck, and waist circumference; for a woman, hip circumference is included too.

What information do I need to use the Body Fat Percentage Calculator?+

Estimate body fat percentage with the Navy tape method or a quick BMI-based comparison using height, weight, sex, and body measurements.

How accurate is the Body Fat Percentage Calculator?+

Body Fat Percentage Calculator applies the formula and assumptions shown on this page. Results may be rounded for readability, so verify changing rates, thresholds, medical guidance, or legal rules with the cited source or a qualified professional.

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Health guide

How to use the Body Fat Percentage Calculator

Estimate body fat percentage with the Navy tape method or a quick BMI-based comparison using height, weight, sex, and body measurements. The page also explains the navy body fat estimate and shows a practical example: For a man, enter height, neck, and waist circumference; for a woman, hip circumference is included too.

  1. 1

    Enter your details

    Enter the Navy tape method or a quick BMI-based comparison using height, weight, sex, and body measurements, then complete any other fields shown in the calculator.

  2. 2

    Check the calculation

    Review the result alongside the navy body fat estimate: Men: 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76; Women: 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387.

  3. 3

    Compare scenarios

    Change one or more inputs to see how they affect the body Fat Percentage Calculator result before you use the estimate.

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