DUI Basics
Blood Alcohol Content (BAC) Limits by State
What Is the Legal Blood Alcohol Limit for Driving?
The legal blood alcohol limit for drivers 21 and older is 0.08 in every state except Utah, where it is 0.05. Commercial drivers face a 0.04 limit, and drivers under 21 face a limit of 0.02 or lower, with 13 jurisdictions allowing no measurable alcohol at all. You can still be charged below these numbers if alcohol impaired your driving.
The legal blood alcohol limit for drivers 21 and older is 0.08 in 50 of the 51 jurisdictions (50 states and DC). Utah is the exception at 0.05. That number is the “per se” limit: at or above it, you can be convicted on the test result alone, without any other proof that you were impaired.
But 0.08 is not the only number that matters. There is a lower limit for commercial drivers, a much lower one for drivers under 21, and in most states a higher tier that brings tougher penalties. And in every state, you can be charged below the limit if alcohol affected your driving.
The Legal Blood Alcohol Limit: 0.08 Everywhere but Utah
Every jurisdiction sets an adult limit, and all but one set it at 0.08. NHTSA confirms the national picture: all 50 states, DC and Puerto Rico make it illegal to drive at 0.08 or higher, and Utah set a lower threshold of 0.05 that took effect on December 30, 2018.
In Utah, that means a test result of 0.05 is enough for a per se DUI charge (Utah Code § 41-6a-502). If you were stopped in Utah, the limits you read for other states do not apply to you. Utah is strict at the other limits too. A driver under 21 may not drive or be in actual physical control of a vehicle with any measurable alcohol, and Utah’s higher tier starts at 0.16. The Utah penalties page shows what a first charge carries.
What BAC Measures
BAC stands for blood alcohol concentration, sometimes called blood alcohol content. It is the amount of alcohol in a set amount of blood. NHTSA states it in grams per deciliter, so 0.08 means 0.08 grams of alcohol per deciliter (100 milliliters) of blood.
State laws use the same scale, and many set a matching breath standard. Maine’s law, for example, sets the limit at 0.08 grams of alcohol per 100 milliliters of blood or per 210 liters of breath (29-A M.R.S. § 2411). New York’s counts a result shown by chemical analysis of blood, breath, urine or saliva (N.Y. Veh. & Traf. Law § 1192).
The law measures concentration, not drinks. No state sets a number of drinks that keeps you under the limit, so the number that matters is the test result.
Three Limits, Depending on Who Is Driving
States set three separate limits: one for adults, one for commercial drivers and one for drivers under 21.
| Driver | Most common limit | Range across the 50 states and DC |
|---|---|---|
| Adult, 21 and older | 0.08 (50 of 51) | 0.05 in Utah to 0.08 everywhere else |
| Commercial vehicle | 0.04 | 0.04 in every state that lists a commercial limit; also the federal standard |
| Under 21 | 0.02 (36 of 51) | Any measurable amount in 13, 0.01 in 2, 0.02 in 36 |
Commercial Drivers: 0.04
Federal rules bar a commercial driver from reporting for or staying on duty in safety-sensitive work at an alcohol concentration of 0.04 or more (49 CFR 382.201). NHTSA notes that operating a commercial vehicle at 0.04 or above violates federal regulations and may also lead to criminal charges. Every state that lists a commercial limit sets it at 0.04 for anyone driving a commercial vehicle. California applies the 0.04 limit to drivers carrying paying passengers as well. The DUI with a CDL guide covers what a DUI means for a commercial license.
Drivers Under 21: Zero Tolerance
Every jurisdiction sets a lower limit for drivers under 21. Of the 51, 36 set it at 0.02, and 2, California and New Jersey, set it at 0.01. The strictest 13 allow no measurable alcohol at all: Alaska, Arizona, DC, Illinois, Maine, Maryland, Minnesota, North Carolina, Oklahoma, Oregon, Texas, Utah and Wisconsin.
These under-21 rules often work differently from an adult DUI. In Florida, a 0.02 result for a driver under 21 leads to an administrative license suspension, not a criminal DUI by itself. In New York, 0.02 to 0.07 is handled at a DMV hearing under the Zero Tolerance Law, while 0.05 or more can be charged as DWAI or DWI in criminal court. California has two lines: 0.01 is unlawful for drivers under 21, and 0.05 or more is a separate offense. The underage DUI guide compares the penalties.
Limits (Adult / CDL / Under 21) by State
From each state's statutes, DMV and court pages, checked October 2026. Each state's page links its sources.
High-BAC Tiers: When a Higher Number Means a Harsher Charge
Most states punish a high test result more severely than a result just over 0.08. Of the 51 jurisdictions, 46 set a higher BAC tier. Its name varies: extreme DUI in Arizona, aggravated DWI in New York and New Mexico, and “highly intoxicated driver” in Hawaii.
| Higher tier starts at | Number of jurisdictions | Examples |
|---|---|---|
| 0.10 | 1 | Pennsylvania |
| 0.15 | 28 | Arizona, California, Florida, Texas, Wisconsin |
| 0.16 | 10 | Illinois, Minnesota, Nevada, New Mexico, Utah |
| 0.17 | 3 | Michigan, Ohio, South Dakota |
| 0.18 | 1 | New York |
| 0.20 | 3 | DC, Idaho |
0.15 is the most common threshold by far. Pennsylvania starts lowest, at 0.10 (75 Pa.C.S. § 3802). A few states sit well above it: New York at 0.18, and DC and Idaho at 0.20. Idaho calls its tier excessive alcohol concentration.
What the tier changes depends on the state. In Michigan, a first OWI carries up to 93 days in jail, but up to 180 days at 0.17 or more (Mich. Comp. Laws § 257.625). In Maine, a first OUI at 0.15 or more carries at least 48 hours in jail (29-A M.R.S. § 2411), and in Kansas 0.15 raises the administrative license penalties (K.S.A. 8-1014). Your state’s penalties page lists the exact difference, and the DUI penalty estimator lets you compare tiers.
NHTSA’s figures show how often high results appear in fatal crashes. Of the 12,429 people killed in alcohol-impaired-driving crashes in 2023, 67 percent died in crashes where at least one driver had a BAC of 0.15 or higher.
The table below has every state’s adult, commercial and under-21 limits and its high-BAC threshold.
You Can Be Charged Below the Legal Limit
The 0.08 number is one way to prove the offense, not the only one. Driving while under the influence is also a crime, whatever your test result, as these state laws show.
California’s law puts the two side by side: one subdivision bars driving under the influence of any alcoholic beverage, and the next bars driving at 0.08 or more (Cal. Veh. Code § 23152). Texas defines “intoxicated” as either losing the normal use of your mental or physical faculties or having an alcohol concentration of 0.08 or more (Tex. Penal Code § 49.01). New York goes further with a separate, lower charge for driving while your ability is impaired by alcohol (N.Y. Veh. & Traf. Law § 1192). Colorado has a similar DWAI charge.
So a result of 0.06 does not end the case. A prosecutor can still try to prove that alcohol impaired you.
How BAC Is Tested After an Arrest
BAC can be measured from breath, blood or urine, and state laws name which tests count. New York’s, for example, accepts chemical analysis of blood, breath, urine or saliva, and DC’s sets 0.08 for blood or breath and 0.10 for urine. Refusing a test carries consequences of its own, separate from failing it. The implied consent guide compares them state by state.
A failed test also starts the clock on your license. In many states, the licensing agency suspends your license separately from the court case, and you have only a short time to request a hearing. Use the DUI deadline calculator with your arrest date to find your last day.
What the Federal Numbers Show About Alcohol and Driving
NHTSA counts a crash as alcohol-impaired when any driver involved had a BAC of 0.08 or higher. In 2023, 12,429 people died in those crashes, about one every 42 minutes, which was 30 percent of all traffic deaths in the country. The rate of alcohol impairment among drivers in fatal crashes was three times higher at night than during the day.
NHTSA’s own advice is simple: plan a sober ride before you go out, and if you have been drinking, use a taxi, a ride-hailing service or a sober friend.
What to Do if You Tested Over the Limit
- Write down your arrest date and the test result on your paperwork, if it shows one.
- Check your license hearing deadline with the deadline calculator.
- Open your state page from the state list for the exact limits, high-BAC penalties and the hearing process, or compare every state on the state law comparison.
- Read what happens after a DUI arrest and the first DUI guide so you know what comes next.
- Talk to a lawyer licensed in your state, the state bar’s lawyer referral service, or the public defender. A lawyer can review how the test was given and whether the result can be challenged.
If your charge uses a different name, such as DWI or OWI, the limits work the same way. The DUI vs DWI guide explains each state’s term.
Frequently Asked Questions
How Many Drinks Put You at 0.08?
There is no number set in law. Every state limit measures the concentration of alcohol in your blood or breath, not how many drinks you had, so no drink count keeps you safely under it. NHTSA's advice is to plan a sober ride before you drink.
What Does a BAC of 0.08 Mean?
It means 0.08 grams of alcohol per 100 milliliters of blood, the same as 0.08 grams per deciliter, the unit NHTSA uses. Many state laws also set the equivalent for breath, such as Maine's 0.08 grams per 210 liters of breath (29-A M.R.S. § 2411).
Why Is Utah's Limit Lower?
Utah lowered its limit for drivers to 0.05, which took effect on December 30, 2018, according to NHTSA. It is the only state with an adult limit below 0.08. See the Utah penalties page for what a charge carries there.
Is the Commercial Limit 0.04 Even in My Own Car?
No. The 0.04 limit applies while you operate a commercial motor vehicle, and federal rules bar a driver from performing safety-sensitive functions at 0.04 or more (49 CFR 382.201). In your own car the adult limit applies. For what a DUI means for a commercial license, see the CDL guide.
Can I Be Charged With DUI the Morning After Drinking?
Yes, if alcohol is still in your system at or above the limit, or still impairs you, when you drive. The law looks at your condition while driving, not when you stopped drinking. Washington's under-21 law, for example, measures alcohol within two hours after driving (RCW 46.61.503).
What Happens if I Refuse the Breath Test?
Refusing a test has consequences of its own, separate from failing it, and they vary by state. The implied consent guide compares the refusal penalties state by state.
More on DUI Basics
- DUI vs DWI vs OWIWhat each term means and which states use which
- What OWI MeansOperating while intoxicated, and the states that use the term
- Implied ConsentWhat refusing a breath or blood test costs you, state by state
- DUI CheckpointsWhich states allow sobriety checkpoints and where agencies announce them
- What Happens After a DUIThe arrest, license deadline, court process and what comes after
- Finding a DUI LawyerWhat a DUI lawyer does, public defenders, and how to check a lawyer's license
This guide explains DUI law in plain language from official sources. It isn't legal advice; laws differ by state and change, and a lawyer licensed in your state can advise on your case.