DUI vs DWI: Understanding the Difference

A DUI or DWI charge is a serious offense. The financial and legal consequences are intense, not to mention the emotional toll for all those involved. Hopefully, no one was injured by the driving that resulted in a DUI or a DWI, and preventing drunk driving should now be a major priority. If you’re still wondering about the difference between a DUI and a DWI, read on to learn about the distinctions, the repercussions, and tips to steer clear of both.

Blood Alcohol Content

Each state has unique laws regarding DUIs and DWIs, laws that vary greatly. There’s one thing all states have in common: a .08% Blood Alcohol Content limit. Blood Alcohol Content, or BAC, indicates a certain percentage of alcohol in the bloodstream. For example, a BAC of .10% means that for every 1,000 parts blood, there is 1 part alcohol present. BAC can be determined by a breathalyzer test, blood test or urine sample. 

Technical talk aside, BAC simply provides a standardized measure for determining the extent to which a person is affected by alcohol. A BAC test is not required in all states in order to charge a person with a DUI or DWI. These charges can also be allocated based on a field sobriety test, dangerous driving behavior or suspicion of the influence of alcohol. Most charges are given based on a combination of indicators. In fact, even if you have a BAC lower than .08% and fail a field sobriety test, you can still be issued a DUI.


DUI stands for “Driving Under the Influence.” A DUI indicates impaired or reckless operation of a motor vehicle, due to inhibited functionality brought on by alcohol consumption. The federal legal limit to drive in the United States is .08%, and a DUI will be given when this limit is broken or another measure of sobriety is failed.

DWI stands for “Driving While Impaired.” Some states use the DWI acronym to mean “Driving While Intoxicated” (and in these states, a DWI is essentially the same thing as a DUI). In states where a DWI means “Driving While Impaired,” this charge usually indicates drug usage. A DWI can be given for use of both prescription and recreational drugs.

Both DUIs and DWIs are issued when a person drives a vehicle in an erratic manner while under the influence of a substance. Typically, a DWI is a more serious offense, and some states will reduce a charge from a DWI to a DUI for a first-time offender with a lower BAC.

Additionally, a first-time DUI or DWI is considered a misdemeanor. However, a repeat offense might bring felony charges.

Legal DUI and DWI consequences

The legal consequences for these offenses vary greatly from one state to the next. Some states mandate jail time for first-time offenses (Arizona, Tennessee and Georgia), whereas Wisconsin doesn’t consider a first-time offense a crime, but a civil infraction (like a parking ticket). Despite these major differences, most states implement similar consequences for a DUI or DWI: loss or suspension of driver’s license, court-mandated community service or participation in a driver education program.

Not only are the legal repercussions costly, but the financial toll is significant. First, the fines and court fees associated with a DUI or DWI are considerable. While the fines are high, increased insurance premiums might be what really breaks the bank. The financial effect of a DUI or DWI may impact a person for years. It may also affect employment, as prospective employers can see a DUI or DWI charge when they conduct a background check. 

Practical tips to avoid a DUI or DWI

Never, ever operate a vehicle with a mind-altering substance in your system or when drowsy. Many substances lower your inhibition and ability to think rationally, so don’t drive even if you’re feeling fine. Here are some more practical tips to avoiding a DUI or DWI:

  • Give your keys to a responsible friend or leave them at home
  • Make driving arrangements with a designated driver or a ride-hailing service, like Uber or Lyft
  • If you’re going out, bring a finite amount of cash so you’re limited to how many drinks you can buy
  • If you’re going to someone’s house, consider spending the night

Should I use an IID?

An ignition interlock device (IID) is a breathalyzer test installed into a vehicle, which prevents a person from starting a car until a breath alcohol test is taken. These devices are sometimes court-ordered in response to a DUI or DWI, but can also be purchased and installed as a preventative measure.

Although this article may help clarify the difference between a DUI and a DWI, take your questions and concerns to a local attorney. There are preventative measures you can take to avoid a DUI or a DWI. If you’ve already been charged, the most important thing to do now is avoid another offense – for your safety and the safety of others.

If you find yourself struggling with substance use habits, Rehab After Work is ready to give you the tools you need to distance yourself from damaging, potentially life-threatening behaviors. Call (610) 644-6464 today, or take the time to learn more about all the ways drug and alcohol rehab can help you prevent chronic substance use and restore freedom through recovery.