What Is the Legal BAC in California?

May 8, 2026 | Nafiz M. Ahmed

Driving under the influence is taken very seriously in California, and law enforcement uses blood alcohol concentration (BAC) testing as one of the primary ways to determine whether a driver is legally impaired. If your BAC is at or above the legal limit, you can be arrested and charged with a DUI regardless of whether your driving appeared impaired.

Learning about where these limits stand is important for anyone who drives in California. Below is a breakdown of the state’s BAC laws, as well as what steps to consider if you’ve been charged with a DUI.

BAC Limits for Different Types of Drivers

California does not apply a single BAC standard across the board. The legal limit that applies to you depends on your age, your license type, and what kind of vehicle you are operating at the time.

Here is how the limits break down:

0.08% for drivers 21 years of age or older operating a standard passenger vehicle
0.04% for commercial vehicle operators and those who drive a passenger for hire
0.01% for drivers under the age of 21 and for those who are on DUI probation

Note that you can still face DUI charges even if your BAC is under the applicable limit. Under California Vehicle Code Section 23152(a), an officer can arrest you if they believe your ability to drive was impaired by alcohol to any degree. A BAC reading is powerful evidence of that, but it is not the only factor prosecutors can rely on.

What Happens After a DUI Arrest in California?

A DUI arrest in California triggers two separate proceedings that run on different tracks. The first is the criminal case, which is handled through the court system. The second is an administrative hearing with the California Department of Motor Vehicles (DMV) regarding the status of your driver’s license.

On the criminal side, the penalties you may face depend on factors like whether this is your first offense and whether anyone was injured. For a first-time misdemeanor DUI, potential consequences include:

Up to six months in county jail
Fines that can total $1,000 or more after penalty assessments are added
A license suspension lasting six months or longer
Mandatory enrollment in a DUI education program
Probation lasting three to five years

Repeat offenses carry steeper penalties, and a DUI that results in injury to another person can be charged as a felony. A fourth DUI offense within ten years can also be elevated to a felony charge.

As for the DMV hearing, you only have 10 days from the date of your arrest to request one. If you miss that window, your license suspension goes into effect automatically. Winning the hearing can allow you to keep your driving privileges while the criminal case moves forward.

Can BAC Evidence Be Challenged?

Yes, in many cases. BAC results are not always as airtight as they may seem. There are a number of ways a defense attorney can challenge this type of evidence in court.

For example, breathalyzer devices need to be properly calibrated and maintained on a regular schedule. If the device used in your case was not serviced according to protocol, the results may be unreliable. Blood test samples can also be compromised through a break in the chain of custody and other means. Beyond the testing itself, your criminal defense attorney may also question whether the traffic stop that led to your arrest was lawful in the first place.

Contact a San Jose DUI Lawyer at Ahmed & Sukaram, Criminal Defense Attorneys to Schedule a Consultation

A DUI charge in California can affect your freedom and future opportunities dramatically. If you are facing charges, setting up a free consultation with a San Jose criminal defense attorney as soon as possible gives you the best chance of building a successful defense. Contact Ahmed & Sukaram, Criminal Defense Attorneys, today to get started and learn about what you should do next to protect your rights.

For more information, please contact our criminal defense law firm of Ahmed & Sukaram, Criminal Defense Attorneys at the nearest location for a consultation.

Ahmed & Sukaram, Criminal Defense Attorneys – San Jose Office
1625 The Alameda, Suite 405, San Jose, CA 95126
(408) 217-8818

Ahmed & Sukaram, Criminal Defense Attorneys – Redwood City Office
600 Allerton St Suite 201G, Redwood City, CA 94063
(650) 299-0500