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California uses the standard 0.08% legal limit for drivers 21 and over, the same number used in every state except Utah. But "the same number" does not mean the same result for everyone. Your weight, sex, how fast you drink, and whether you have eaten all change how quickly you get there, and how long it takes to get back under it.
This blood alcohol concentration calculator lets you log your actual drinks as the night goes on and see a live estimate of your BAC against California's 0.08% limit, along with your peak reading and roughly how long until you are sober.
● 3 calculation models ● State and country legal limits ● Live BAC curve
Used to estimate body water distribution — the biggest factor in BAC accuracy.
Average is 0.015%/hr. Genetics, liver health, and tolerance shift this between 0.010–0.020%/hr.
Log each drink as you go for the most accurate live curve.
Modeled absorption & elimination curve for your full session.
0 / 8 glasses
Water helps prevent dehydration and eases next-day symptoms, but it does not lower your BAC or speed up alcohol metabolism. Only time does that.
General effects by approximate BAC level. Individual response varies significantly.
| BAC | Typical Effects |
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That last one surprises a lot of people. If you drive for Uber or Lyft in California, you are held to the same 0.04% standard as a commercial truck driver whenever you have a passenger, not the regular 0.08%.
Two people who had exactly the same three drinks over the same two hours can land on very different BAC numbers. A smaller person, or someone with a lower percentage of body water, ends up with a higher concentration from the same amount of alcohol. This is why this calculator asks for weight, height, age, and sex, and why it offers the Watson body-water model in addition to the older Widmark formula. It is trying to estimate your actual body chemistry, not just count drinks.
Food matters too. Eating before or while drinking slows down how fast alcohol gets into your bloodstream. It does not lower the total amount of alcohol you end up absorbing, but it spreads out the peak, which is why the calculator has a food toggle that shifts the curve.
California runs sobriety checkpoints regularly, especially around holidays, so “I only had a couple” is not a great plan if you are anywhere close to the limit. A first DUI in California can mean fines, license suspension, and mandatory DUI education classes, even without a crash or injury involved. The exact penalties depend on your record and the specifics of the stop, so for legal questions, a local DUI attorney or the California DMV is the right resource, not a calculator.
QUESTIONS
0.08% for drivers 21 and over. It drops to 0.04% for commercial drivers and for rideshare or taxi drivers with a passenger, and to 0.01% for drivers under 21.
Yes. California can charge a “wet reckless” or impaired driving offense even under 0.08% if an officer believes your driving was actually impaired, and the lower limits for commercial, rideshare, and underage drivers apply regardless of the standard 0.08% line.
The body eliminates alcohol at a fairly steady rate, roughly 0.015% per hour on average, though this varies by person. This calculator estimates your personal time back to 0.00% based on how much you drank and your body’s estimated elimination rate, not a flat number.
No. Neither one changes how fast your liver processes alcohol. Time is the only thing that actually lowers your BAC.
Research and official guidance
We use primary government and public-health sources to support the legal-limit, standard-drink, impairment, and alcohol-metabolism information on this page.
Important: Laws and individual responses to alcohol can vary. This calculator provides an estimate only and must never be used to decide whether it is safe or legal to drive.