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Blood Alcohol Content Estimator (Widmark Formula)

Estimate blood alcohol content using the Widmark formula from grams of alcohol consumed, body weight, and time.

Methodology reviewed 2026-07-27. See our review process.

Formula and method

This calculator uses the values you enter and applies the calculation immediately in your browser. The main output formulas are:

  • Estimated BAC: Math.max(0, (alcoholGrams/(weightKg*1000*genderConstant))*100 - 0.015*hoursElapsed)

Some formulas are undefined for certain input combinations, such as division by zero, equal x-values in a slope calculation, or logarithms of non-positive numbers. In those cases the live tool reports that the result is undefined instead of displaying Infinity or NaN.

Examples

  • Example: with Alcohol consumed = 28 g, Body weight = 75 kg, Distribution ratio (male≈0.68, female≈0.55) = 0.68, Hours since drinking began = 2 hours, this calculator returns Estimated BAC = 0.0249 %.
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Frequently asked questions

Is Blood Alcohol Content Estimator (Widmark Formula) free to use?

Yes. Blood Alcohol Content Estimator (Widmark Formula) is completely free, has no usage limit, and does not require an account, email, or API key.

Does Blood Alcohol Content Estimator (Widmark Formula) store or upload my data?

No. Blood Alcohol Content Estimator (Widmark Formula) calculates everything locally in your browser. Nothing you type is sent to a server or stored by SpecWhale.

How accurate is Blood Alcohol Content Estimator (Widmark Formula)?

Blood Alcohol Content Estimator (Widmark Formula) 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 Blood Alcohol Content Estimator (Widmark Formula) on my own website?

Yes. Use the "Embed this tool" snippet on this page to add a free, working copy of Blood Alcohol Content Estimator (Widmark Formula) to your own blog post or page.

SEO and sharing notes

This page has a single clean canonical URL, descriptive metadata, breadcrumb structured data, and internal links to related tools. Supported calculators and converters can also copy a prefilled share link without changing the canonical index URL.