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Enter measurement inputs
BFThe reference page uses body measurements and shows multiple body-composition outputs. This version keeps the same circumference-based method but updates the estimate live in place.
Health directory
Open categoryThis calculator is part of the health section. Keep the current tool open for calculation, then use the related calculators below to compare nearby planning tasks.
Health calculator
Body Fat Calculator
Use a fuller body-fat calculator when body weight alone is not enough. This page estimates body-fat percentage, fat mass, and lean mass from practical body measurements.
How to use this calculator
Body-fat calculator guide
Circumference-based body-fat methods use height with key tape measurements to estimate how much of total body weight is lean mass versus fat mass. The reference page follows the same idea. This version keeps the result, composition split, and category table in one place so the estimate is easier to interpret without leaving the input area.
- Use consistent tape-measure technique each time so comparisons over weeks or months are more useful than single one-off measurements.
- Read fat mass and lean mass together because body-fat percentage alone says less when total body weight changes over time.
- Treat circumference-based estimates as practical approximations, not as laboratory-grade measurements.
Formula / method
Formula / method
This body fat calculator uses the existing ToolModule calculation model for the inputs shown above. The page keeps the original formulas and result logic intact, then presents the output in a clearer working layout.
- Start with the required inputs in the form above.
- The calculator applies the existing ToolModule calculation logic for this tool.
- Review the result cards, tables, and charts together before making a real-world decision.
Example calculation
Review the current live example
The example below reflects the current values shown in the calculator above, so it updates as you change the form without altering the calculation logic itself.
Example inputs
SexMale
Age30
Height (cm)178
Waist (cm)86
Neck (cm)39
Example outputs
Body fat percentage16.44%
CategoryFit
Body fat mass12.8 kg
Estimated lean mass65.2 kg
Disclaimer
Use results as planning guidance only
Results are for reference only and do not constitute medical, nutrition, or clinical advice. Use professional guidance when a health or treatment decision is involved.
- Do not treat calculator output as financial, investment, medical, or legal advice.
- Check assumptions, dates, tax rules, and provider-specific terms before acting on a result.
- Use official documents or professional guidance when the decision has material consequences.
FAQ
Common Body Fat questions
Is a tape-measure body-fat estimate accurate?
It is a practical estimate rather than a lab test, but it can still be very useful for tracking change when measurements are taken consistently.
Why does the calculator ask for different measurements by sex?
Common circumference formulas use different measurement sets for men and women because body-fat distribution patterns differ.
Why keep the chart on the same page instead of separating the result?
The reference site often separates submission and output. Here the composition split and category reference remain attached to the inputs for easier comparison.