Calculation limitations
The calculator uses a simplified Widmark-based equation with reported drink quantities, body mass, a selected distribution factor and assumed elimination. It does not measure alcohol, model every absorption pattern or account for all individual physiology. Actual BAC may be outside the displayed sensitivity range.
A zero result is a mathematical output, not proof of zero alcohol or absence of impairment. The range is not a confidence interval. More decimal places do not make the inputs or biological assumptions exact.
Health information and emergencies
Information is general and does not replace a clinician's assessment. Do not use it to diagnose illness, change medication or dismiss symptoms. If someone is difficult to wake, breathing slowly or irregularly, having a seizure or otherwise seriously unwell after drinking, contact local emergency services promptly.
Do not assume a severely intoxicated person can simply sleep it off. Follow emergency instructions. The site and its email inbox are not monitored emergency services.
Driving and legal information
No drink count, estimated BAC or elapsed-time calculation on this site establishes that driving is safe or lawful. Legal requirements differ by jurisdiction and driver category and may change. Consult the relevant official authority or a qualified legal professional for a specific question.
Choose transport that does not require you to drive after drinking. The site does not calculate a permitted alcohol dose, offer test-evasion methods or certify a future driving time.
Sources and corrections
Links to public-health and government references support further reading; they do not imply endorsement. We do not claim a professional medical review or regulatory approval. Report a suspected error to info@bac-calculator-us.com.
Estimates, measurements and the gap between them
Throughout this site, three kinds of statements appear and they are not interchangeable. An estimate is a calculation from self-reported inputs under published assumptions. A measurement is a physical result — a breath sample, a blood draw, a laboratory assay. A legal determination is what a court or authority decides a result means under a specific statute. Our pages can explain all three; we can only produce the first, and only you can be measured.
This is why every calculator output on the site is labeled as a modeled range rather than a single confident number, and why the sensitivity range is described as changing one assumption rather than as a confidence interval. When an estimate and a measurement disagree, the measurement wins for practical purposes — and when a measurement and a legal determination differ, the determination governs. Reading our content in that order prevents most misunderstandings.
Situations this content must not be used for
Some uses of this site would be actively dangerous, and we want the boundary stated in one place rather than implied. Do not use any estimate to decide whether to drive, operate machinery, provide care for others, or perform safety-critical work. Do not use the detection-window discussion to plan around an upcoming urine, breath or hair test — the pages explain testing so readers can understand results, not evade them. Do not use the standard-drink content to pace drinking to a target concentration, and do not treat any “how long to sober up” explanation as a clearance clock.
Do not use this site to assess another person's condition in an emergency. Signs of alcohol poisoning — unconsciousness that is hard to rouse, slow or irregular breathing, seizures, cold or bluish skin, vomiting while unresponsive — require emergency services immediately, whatever any calculation says. A low estimate has never been a reason to delay that call, and the site's email inbox is not a monitored emergency channel.
Reliance, links and the limits of our own pages
We take source discipline seriously, but a small educational site cannot guarantee continuous accuracy. Legal thresholds change; guidance is revised; pages carry the date they were last checked, and a reader making a consequential decision should follow the live official source linked beside the claim rather than our snapshot of it. Where our pages and an official source diverge, the official source is authoritative, and we should be emailed about the discrepancy.
External links are provided for context and their content belongs to their operators. No link implies partnership, endorsement or any relationship beyond citation. Our pages may contain errors despite our process; the about page describes how corrections are made in place with a new edition date. Using this site means treating it as one honest voice among authoritative sources — never as the final one.