Free online calculator
Body Fat Calculator
Estimate body fat percentage using waist, neck, height, and sex-based formulas.
Quick Answer
How It Works
Body fat is estimated from height and body circumferences with sex-specific equations.
- Select sex and enter height, neck, and waist measurements.
- For females, add hip measurement.
- Review estimated body fat percentage.
Examples use USD-style formatting. Tax rates, fees, and legal rules vary by country and change over time — treat results as estimates and confirm important numbers with a qualified professional.
Interactive Calculator
Estimated body fat: 16.94%
Example Use Case
Two people with similar BMI can show different body fat percentages due to body composition differences.
Detailed Guide
Body-fat estimation complements BMI by adding composition context. Two people with identical BMI can differ significantly in fat-to-lean distribution.
Measurement consistency is critical. Tape placement and posture differences can change outputs even when body composition is unchanged.
Trend tracking over time is usually more useful than one standalone reading. Stable measurement method improves signal quality.
Use estimates as directional guidance for training and nutrition planning, and combine with professional advice where health decisions require precision.
Assumptions and Limits
This is an estimate and should not replace clinical body composition assessment.
Common Mistakes to Avoid
- Incorrect tape placement while measuring circumferences.
- Using mixed units accidentally.
- Treating estimate as medical diagnosis.
FAQ
Can I use this calculator for free?
Yes. This tool is free and designed for practical day-to-day decisions.
Why might results differ from another website?
Differences usually come from rounding rules, assumptions, or region-specific formulas.
Is this suitable for legal or financial advice?
No. Treat outputs as guidance and validate with qualified professionals for final decisions.
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How we choose formulas and check results: Methodology · Last reviewed 2026-07-25