BAC legal limit by state for adult, commercial and young drivers

Every state and DC set the adult limit at 0.08, with one exception. Utah uses 0.05, a rule that has applied since the end of 2018 to residents and visitors alike. At or above the listed number, a driver 21 or older can be charged on the strength of a breath or blood result alone.

The adult column says nothing about lower levels. Each state also has a general impaired driving offense that does not depend on a number, so a driver at 0.06 who weaves across lanes can still face a charge. Our legal alcohol limit page explains how per se and impairment charges work together.

The 0.04 figure comes from federal rules that every state enforces for drivers operating a commercial motor vehicle. It applies while driving a vehicle that requires a commercial driver's license, regardless of where the license was issued. The Federal Motor Carrier Safety Administration (FMCSA) publishes these rules, including a 24 hour out of service order for any detectable alcohol while on duty.

In a personal car, a commercial license holder is judged by the ordinary adult limit, but a conviction there can still cost them the commercial license. Employers in regulated transportation also test drivers under 49 CFR Part 40, described in our guide to dot breath alcohol testing.

All states have zero tolerance laws for drivers below the legal drinking age. Most set a low numeric threshold so that trace amounts and normal instrument tolerance do not trigger a case, and that threshold is often 0.02. Several states go further. California and New Jersey use 0.01, while Alaska, Arizona, the District of Columbia, Illinois, Maine, Minnesota, North Carolina, Oklahoma, Oregon, Texas, Utah and Wisconsin prohibit drivers under 21 from driving with any measurable alcohol.

Penalties under these rules usually begin with an administrative license suspension and can include fines, education programs and longer suspensions for repeat cases. A young driver at or above the adult limit faces the adult offense as well.

Enhanced penalty thresholds:

many states add a higher tier, often somewhere around 0.15 to 0.20, that brings tougher penalties

Implied consent:

the length of a license suspension after refusing an evidential test, and how refusal can be used in court

Ignition interlock rules:

whether an ignition interlock device is required after a first offense or only after repeat or high BAC offenses

Look back periods:

how many years an earlier offense counts toward repeat penalties

Administrative steps:

deadlines for requesting a hearing after a license suspension

Search for your state's Department of Motor Vehicles or Department of Public Safety and look for pages on impaired driving, DUI or DWI. Most states publish a driver handbook with a chapter on alcohol and the law, and that handbook is usually the clearest plain language source.

• Open the official state DMV website, ending in .gov
• Find the driver handbook or the impaired driving section
• Look for the per se limit, the under 21 rule and the refusal penalty
• For commercial drivers, read the CDL manual and the FMCSA rules
• For national context and research, see the National Highway Traffic Safety Administration (NHTSA)

If you are dealing with a charge, speak with a licensed attorney in that state.

The table tells you where the lines are. It cannot tell you where you are. The bac calculator estimates a range from your drinks, weight and time, and the bac chart shows typical levels at a glance. For a reading of your actual breath, choose a fuel cell breathalyzer or start from our best breathalyzer ranking. None of these tools can confirm that driving is safe, so plan your ride before the first drink.

A calculator only estimates. To measure, a fuel cell breathalyzer reads your actual breath.