What Is The Legal Alcohol Limit In California

Are you a Californian wondering how many drinks put you over the limit? If so, understand that California has clearly defined laws regarding the legal alcohol limit for drivers. 

This article provides helpful and crucial information about those limits, DUI laws, penalties, and tips to help safeguard your driving rights.

Let’s get started on a journey to safer roads and better awareness!

What is BAC? How is it Measured? 

legal alcohol limit california

BAC, or Blood Alcohol Concentration, represents the amount of alcohol circulating in your bloodstream. It’s not about how many drinks you’ve had but rather how much alcohol is present in your blood.

The procedure to measure BAC varies and includes methods like breath, blood, and urine tests. The most commonly used method by law enforcement is the breathalyzer test due to its ease of use during traffic stops.

However, it’s essential to know that these tools don’t directly measure your BAC—they estimate it based on the alcohol content in your breath.

Understanding California’s DUI Laws

In California, the legal blood alcohol concentration (BAC) limit for drivers 21 years and older is 0.08%. If your BAC clears above this threshold, you could face charges under the ‘per se’ DUI policy. This measure allows law enforcement to arrest drivers with a BAC of 0.08% or higher.

The Golden State implements stricter regulations for different categories of drivers. This includes commercial drivers who follow the significantly lower BAC limit of 0.04%. Additionally, underage motorists in California have no room for risk-taking as the state’s zero tolerance laws apply a near-nil allowable limit of 0.02% BAC to discourage underage drinking and driving.

A person operating a vehicle on Californian roads inherently agrees to submit their breath, blood, or urine sample. Refusal may lead to serious consequences such as immediate license suspension and penalties identical to those accompanying DUI convictions.

Legal Alcohol Limit in California

California’s legal alcohol limit for adult drivers is 0.08% BAC. However, there are different limits for underage drivers and those on DUI probation. Keep reading to learn more about the specific BAC levels and their implications!

BAC limits for Adult Drivers

In California, the law limits the amount of alcohol an adult driver can have in their system. Specifically, this limit is a Blood Alcohol Concentration (BAC) of 0.08%.

It’s vital to understand that even if you feel okay to drive, your BAC could still be at or over this legal limit; subjective feelings of drunkenness don’t always correlate with BAC levels.

The state heavily enforces these drunk driving laws for all motorists’ safety and works tirelessly to maintain lower incidents related to alcohol consumption and driving.

Zero Tolerance Law for Underage Drivers

California has a zero-tolerance law for underage drivers regarding alcohol consumption. This means that anyone under the age of 21 caught driving with any amount of alcohol in their system can face serious consequences.

The legal blood alcohol concentration (BAC) limit for underage drivers in California is just 0.01%. If an underage driver is found to have a BAC level above this limit, they will lose their license.

These strict laws have been proven effective, as studies have shown a 10% reduction in nighttime single-vehicle crashes among underage drivers since implementing the zero-tolerance policy.

Zero Tolerance Law for Drivers on DUI Probation

Drivers on DUI probation in California are subject to a zero-tolerance law. This means they cannot have any measurable amount of alcohol in their system while driving.

If their blood alcohol concentration (BAC) is 0.04% or higher, they can be charged with a DUI offense. These drivers must understand the strict rules and consequences they face under this law, as violating it can lead to serious penalties and further legal trouble.

DUI Penalties in California

DUI penalties in California can have serious consequences. You could face up to six months in jail and significant fines if convicted. In certain circumstances, such as driving under the influence with a minor in the vehicle or causing an accident resulting in harm or death, felony DUI charges may apply.

Not only will a conviction result in fines of approximately $3,000 but you may also be required to complete a 30-month drug/alcohol treatment program. Additionally, if your DUI involves injury to another person, you could face imprisonment.

It’s important to note that the average total costs for fines, fees, and alcohol treatment programs for a DUI in California range from $7,000 to $11,000. These penalties underscore the seriousness of drinking and driving offenses in the state.

What Happens During a DUI Traffic Stop and Arrest?

During a DUI traffic stop and arrest, the police officer may conduct pre-arrest BAC tests, such as field sobriety tests or portable breathalyzer tests, to determine if there is probable cause for an arrest.

Pre-Arrest BAC Tests

During a DUI traffic stop and arrest, you may be asked to take a pre-arrest BAC test. This test can include a Breathalyzer or other chemical tests to measure your blood alcohol concentration (BAC) level.

A BAC level of 0.01% or more is considered positive on the test. It’s important to know that refusing to take this test can lead to a one-year license suspension under implied consent laws.

If you are arrested for DUI, you may also be required to undergo a BAC test that is admissible as evidence in court.

Post-Arrest BAC Tests

If you are arrested for drunk driving in California, after the arrest you will be asked to take a post-arrest BAC test. This test is important because it measures your blood alcohol concentration (BAC) and provides evidence for court use.

If your BAC level is found to be 0.01% or more during this test, your driving privilege will be suspended for one year. Most people take a DUI breath test for this measurement, which is commonly used and generally accurate.

It’s crucial to understand the importance of complying with a post-arrest BAC test as it can significantly affect your DUI case and driving privileges moving forward.

Defending Yourself Against DUI Charges

It’s important to remember that BAC testing methods, such as breathalyzer tests, may not always be accurate and can produce falsely high results. Challenging the accuracy of blood alcohol concentration (BAC) results is one defense strategy that can be used when facing DUI charges. 

Questioning the reliability of these tests and presenting evidence to support your case could weaken the prosecution’s argument against you.

Another successful DUI defense tactic is challenging the legality of the traffic stop or arrest itself. Law enforcement officers must have reasonable suspicion to pull you over and probable cause to make an arrest.

If these requirements were not met, it may be possible to have your charges dismissed.

Additionally, repeat DUI convictions in California carry stricter penalties than first-time offenses. However, if you can successfully defend yourself against DUI charges by challenging BAC test results or other aspects of your arrest, it may help prevent a conviction altogether.

Defending yourself against DUI charges can lead to avoiding conviction and the associated penalties. It’s vital to consult with an experienced attorney who specializes in DUI defense strategies to build a strong case on your behalf.


The legal alcohol limit in California is 0.08% for most adult drivers, but for people on probation and drivers under 21 circumstances are different  It is illegal to operate a motor vehicle with a blood alcohol concentration (BAC) of 0.08% or higher. With that said, the test may not be 100% accurate and there are ways to appeal against these charges. 

Share this post

Take your first step, leave the rest to us

Give us a call


Send us a message

Fill out the form to schedule your consultation