DUI vs. DWI: What's the Difference?
DUI and DWI both describe the crime of operating a vehicle while impaired, but the exact term — and whether the two mean different things — depends entirely on your state. Here's how the labels break down and why the penalties matter far more than the acronym.
What the acronyms stand for
DUI means 'driving under the influence.' DWI means 'driving while intoxicated' or 'driving while impaired.' You'll also see OWI (operating while intoxicated), OVI (operating a vehicle impaired), and OUI (operating under the influence) in various states — they describe the same basic offense.
Do DUI and DWI mean different things?
It depends on the state. Many states use just one term for all impaired-driving offenses. Others use both and distinguish them — for example, treating one as more serious, or using one for alcohol and the other for drugs, or basing the label on the driver's blood alcohol concentration. Because there's no national rule, the same conduct can be charged under different names in different states.
The 0.08% rule (and the exceptions)
In every state it is illegal to drive with a blood alcohol concentration (BAC) of 0.08% or higher — this is the 'per se' limit, meaning you can be convicted on the number alone. Commercial drivers are held to 0.04%, and drivers under 21 face 'zero tolerance' limits far below 0.08%. You can also be charged below 0.08% if an officer shows you were impaired.
What actually matters: the penalties
Whatever your state calls it, what affects your life is the penalty — the fine, possible jail, license suspension, and ignition-interlock requirement — and those are set by state law and rise sharply for repeat offenses. See your state's page for the specific penalties by offense.
Find your state’s penalties
Fines, jail, license suspension, and interlock rules are all set state by state — the general rules above only get you so far.
Or try the penalty estimator to filter by offense number and BAC.
Frequently asked questions
Is a DUI worse than a DWI?
Not universally. In some states DUI and DWI are the same charge; in others one is treated as more serious than the other. Because it varies by state, the severity comes from how your state defines and penalizes the offense, not from the acronym itself.
What is the legal BAC limit?
0.08% for most drivers in every state. Commercial drivers are limited to 0.04%, and drivers under 21 are subject to much lower 'zero tolerance' limits. You can still be charged below 0.08% if the officer demonstrates impairment.
What does 'per se' DUI mean?
A 'per se' DUI means you can be convicted based on your BAC alone — at or above 0.08% — without the prosecution having to separately prove your driving was impaired.