Calculateur de Body Fat
Estimate body fat percentage using a simple circumference formula.
Formula and method
This calculator computes Estimated body fat directly in your browser without sending data to an external server.
Mathematical formula
- Estimated body fat:
(() => { if(waist<=neck) return NaN; const value=86.010 × Math.log10(waist-neck)-70.041 × Math.log10(height)+36.76; return value>=0 && value<=100 ? value : NaN; })()
Variables and parameters
- Waist (waist): default value 34 in.
- Neck (neck): default value 15 in.
- Height (height): default value 70 in.
Some formulas are undefined for certain input combinations (such as division by zero or logarithms of non-positive numbers). In those cases the live tool displays an alert instead of NaN.
Embed this tool
Paste this snippet into your own site or blog post to embed a live, working copy of this tool. It links back to the full page on SpecWhale.
Frequently asked questions
What equation and variables does Body Fat Calculator use?
Body Fat Calculator evaluates outputs such as <strong>Estimated body fat</strong> based on inputs including Waist, Neck, Height. Check the Mathematical Method section for the explicit formula.
What should I keep in mind when interpreting Body Fat Calculator metrics?
Health and body calculators provide general estimates derived from standard population equations. Individual physiological differences (such as muscle mass or hydration) can alter personal results.
What happens if I enter invalid or zero values into Body Fat Calculator?
If an input combination is mathematically undefined (such as division by zero or negative square roots), SpecWhale alerts you gracefully rather than returning invalid NaN outputs.
Are my calculations in Body Fat Calculator saved or private?
All calculations are 100% private and run locally in your Web browser. Your numbers are never uploaded to any server, but can be saved locally to your device or exported as CSV/JSON.
Is Body Fat Calculator free to use?
Yes. Body Fat Calculator is completely free, has no usage limit, and does not require an account, email, or API key.
Does Body Fat Calculator store or upload my data?
No. Body Fat Calculator calculates everything locally in your browser. Nothing you type is sent to a server or stored by SpecWhale.
How accurate is Body Fat Calculator?
Body Fat Calculator uses a standard formula (see the Method section above for the exact expression). For high-stakes financial, medical, or legal decisions, confirm the result with a professional or an authoritative source before relying on it.
Can I embed Body Fat Calculator on my own website?
Yes. Use the "Embed this tool" snippet on this page to add a free, working copy of Body Fat Calculator to your own blog post or page.