Estimate Your Blood Alcohol Level
Disclaimer: This tool provides a mathematical estimate based on the Widmark formula. It is NOT a substitute for a breathalyzer and should never be used to decide if you are legally safe to drive. Our BAC Calculator helps you understand how different variables—like your weight and the passage of time—affect alcohol metabolism.
The Variables That Affect BAC
Alcohol affects everyone differently. The Widmark formula accounts for the most critical biological factors:
- Biological Sex Men and women metabolize alcohol differently due to different ratios of body water and the presence of the enzyme alcohol dehydrogenase in the stomach.
- Body Weight A heavier person has more total body water, which dilutes the alcohol in the bloodstream, resulting in a lower BAC than a lighter person who drank the same amount.
- Standard Drinks A 'standard drink' is 14 grams of pure alcohol (e.g., a 12oz 5% beer, a 5oz 12% glass of wine, or a 1.5oz shot of 40% liquor). Craft beers often count as 1.5 or 2 standard drinks.
- Time Elapsed The liver metabolizes alcohol at a strict, linear rate of about 0.015 BAC per hour. You cannot speed this up with coffee or cold showers.
How to Use This Tool
- Upload or Input Data: Select your file or paste your data directly into the tool interface. Everything remains on your device.
- Configure & Process: Adjust any optional settings if necessary. The tool will process your data instantly inside your browser.
- Download Result: Preview the output and click the download or copy button to save your final results.
Frequently Asked Questions
What is the legal driving limit?
In all 50 US states, the legal limit for driving under the influence (DUI) is a BAC of 0.08% for adults over 21. For commercial drivers, it is 0.04%. For those under 21, many states enforce a 'Zero Tolerance' policy of 0.00%.
Can eating food lower my BAC?
Eating food *before* or *while* drinking slows the absorption of alcohol into the bloodstream, blunting the peak BAC. However, eating food *after* you are already drunk does nothing to remove alcohol from your blood faster.
Why shouldn't I trust this calculator to drive?
Mathematical formulas cannot account for your personal liver health, your genetics, what you ate, or interactions with medications. You could be legally over the limit even if the calculator estimates you are under.