Illinois DUI
Penalty Calculator

A first-offense DUI in Illinois carries fines of up to $2,500, jail time of up to 1 year, and a license suspension of 6 months (1 year if test refused). The BAC limit is 0.08%; for drivers under 21 the zero-tolerance limit is 0.00%.

Commercial drivers face a 0.04% limit nationwide.

A DUI charge in Illinois can be based on a per se violation (BAC at or above the legal limit) or on impairment — meaning an officer observed signs of intoxication regardless of BAC level. Drug-impaired driving, including prescription medications and marijuana, falls under the same statute.

Illinois law enforcement officers use standardized field sobriety tests, breathalyzer tests, and blood draws to establish impairment. Refusing a chemical test triggers separate penalties under Illinois's implied consent law.

DUI penalties in Illinois escalate sharply with each subsequent offense. The state uses a Lifetime lookback period to determine whether a new arrest counts as a first, second, or subsequent offense.

Prior convictions outside this window may not count for enhancement purposes, though some states have moved to lifetime lookback periods. Understanding where your case falls in this framework is critical to anticipating potential consequences.

Key reference: 755 ILCS 5/27-2.

Illinois's DUI cases are tried in Circuit Court. Illinois does not allow sobriety checkpoints — they are prohibited by the Illinois Supreme Court as unconstitutional under Article I, § 6 of the Illinois Constitution.

Illinois requires completion of an Alcohol/Drug Evaluation (Risk Assessment) and DUI Risk Education Program as conditions of license reinstatement. SR-22 is required for 3 years.

Illinois's BAIID (Breath Alcohol Ignition Interlock Device) program is mandatory for all license reinstatement after DUI. Illinois's Monitoring Device Driving Permit (MDDP) allows first-time DUI offenders to continue driving during the statutory suspension with an interlock installed.

Illinois's Judicial Driving Permit is available later in the suspension. Cook County (Chicago) has a large DUI call with specialized courtrooms.

Illinois has a cannabis per se impairment standard under the Illinois Vehicle Code.

A first-offense DUI in Illinois carries jail time of up to 1 year, fines of up to $2,500, and a license suspension of 6 months (1 year if test refused). Illinois does not impose mandatory minimum jail time for a first-offense DUI, giving judges discretion to impose alternative sentences such as community service, probation, or alcohol education programs.

Beyond the statutory penalties, a first-offense DUI in Illinois carries significant collateral consequences. These include a permanent criminal record (in most states), dramatically increased auto insurance premiums ($3,000–$5,000+ annually for 3–5 years), mandatory alcohol or drug education classes (typically 12–36 hours), and potential impacts on employment, professional licensing, and child custody.

The total cost of a first-offense DUI — including fines, fees, insurance increases, legal costs, and lost wages — typically ranges from $10,000 to $25,000.

Most first-offense DUI cases in Illinois are classified as misdemeanors. Diversion or deferred adjudication programs may be available for first-time offenders, allowing the charge to be reduced or dismissed upon successful completion of court-mandated conditions.

These programs typically require substance abuse assessment, completion of a treatment program, community service, and a period of monitored sobriety. Eligibility varies by county and judicial district.

Penalties for a second DUI offense in Illinois are substantially more severe than a first offense. Mandatory minimum jail sentences typically apply, fines increase significantly, and license suspension periods are extended.

In Illinois, a second offense within the Lifetime lookback period triggers enhanced penalties that may include mandatory jail time, extended probation, and mandatory installation of an ignition interlock device. The court has less discretion to offer alternative sentencing for repeat offenders.

A third DUI offense in Illinois often crosses the threshold into felony territory. In Illinois, a third offense is classified as a felony, carrying potential state prison time (typically 1–5 years), substantial fines, extended or permanent license revocation, and mandatory substance abuse treatment.

Felony DUI convictions carry long-lasting consequences including potential loss of voting rights, firearm ownership restrictions, and severe employment barriers.

The lookback period in Illinois is Lifetime. This is the window during which prior DUI convictions count as "priors" for sentencing enhancement purposes.

Illinois uses a lifetime lookback, meaning any prior DUI conviction — no matter how old — counts as a prior offense for enhancement purposes. This is the strictest approach and means a person convicted decades ago faces enhanced penalties for any subsequent offense.

Illinois imposes enhanced penalties for aggravated DUI, which typically applies when the driver's BAC is 0.16% or higher — well above the standard 0.08% limit. An aggravated or "high BAC" DUI carries stiffer mandatory minimums, longer license suspensions, and in many cases mandatory jail time even for a first offense.

The elevated BAC level is considered strong evidence of extreme impairment and reckless disregard for public safety.

Beyond high BAC, other aggravating factors in Illinois can elevate a standard DUI charge. Driving under the influence with a minor child in the vehicle (typically under age 16) is a separate or enhanced offense in most states, often adding mandatory jail time and additional criminal charges such as child endangerment.

Causing bodily injury or death while driving under the influence elevates the charge to a felony in virtually every state, with potential prison sentences of 5–20+ years.

Other common aggravating factors include driving on a suspended or revoked license at the time of the DUI arrest, excessive speeding (typically 20+ mph over the limit), driving the wrong way on a highway, and fleeing from law enforcement. Each of these factors can independently increase the severity of the charges and penalties.

In some jurisdictions, multiple aggravating factors can stack, resulting in consecutive sentences.

A DUI arrest in Illinois triggers two separate license actions: an administrative license suspension (sometimes called Administrative License Revocation or ALR) imposed by the DMV, and a court-ordered suspension upon conviction. The administrative suspension takes effect shortly after arrest — often within 30 days — regardless of whether the criminal case has been resolved.

In Illinois, the first-offense administrative suspension is typically 6 months (1 year if test refused). Drivers may request an administrative hearing to challenge the suspension, but strict deadlines apply (usually 10–30 days from the date of arrest).

Illinois requires an ignition interlock device (IID) for first-offense DUI convictions. The IID is a breathalyzer connected to the vehicle's ignition that prevents the engine from starting if the driver's BAC exceeds a preset limit (typically 0.02–0.04%).

The device must be installed at the driver's expense ($70–$150 for installation plus $60–$80 per month for monitoring and calibration). The interlock requirement typically lasts 6–12 months for a first offense, with longer periods for repeat offenders.

Restricted or hardship licenses may be available in Illinois during the suspension period, allowing driving to and from work, school, medical appointments, and court-ordered programs. Eligibility for a restricted license often requires installing an ignition interlock device and providing proof of SR-22 (high-risk) auto insurance.

Driving on a suspended license after a DUI conviction is a separate criminal offense that can result in additional jail time, fines, and extended suspension.

Like all states, Illinois has an implied consent law — by operating a motor vehicle on Illinois roads, you have implicitly agreed to submit to chemical testing (breath, blood, or urine) if an officer has probable cause to believe you are driving under the influence. Refusing a chemical test triggers separate administrative penalties that are often more severe than the penalties for failing the test.

In Illinois, the penalty for refusing a chemical test on a first occurrence is 1-year statutory summary suspension (vs. 6 months for failing).

Refusal to submit to testing is often used as evidence against the driver at trial. Prosecutors can argue that the refusal demonstrates consciousness of guilt — the driver knew they would fail the test.

Some states allow the jury to draw an adverse inference from the refusal. However, refusal also means there is no BAC evidence for the prosecution to present, which can make it harder to prove impairment.

This strategic calculation is one reason drivers sometimes refuse testing despite the administrative consequences.

Illinois law distinguishes between field sobriety tests and chemical tests under implied consent. Drivers can generally refuse field sobriety tests (walk-and-turn, one-leg stand, horizontal gaze nystagmus) without triggering implied consent penalties.

The implied consent law applies specifically to evidentiary chemical testing — typically a breathalyzer at the station or a blood draw. Portable breath tests (PBTs) used roadside may also fall outside the implied consent framework in some jurisdictions.

Consult a Illinois DUI attorney immediately if you are facing refusal charges.

A DUI conviction carries long-term consequences beyond the immediate penalties. The Illinois Criminal Defense Cost Estimator breaks down attorney fees, bail bond costs, and total case expenses by charge severity so you can plan accordingly.

If you're wondering how long you have to file a related civil claim — for example, a personal injury suit arising from a DUI accident — the Illinois Statute of Limitations Lookup covers filing deadlines by cause of action. And if you are dealing with a prior DUI on your record, the Illinois Expungement Eligibility Checker explains whether your record may qualify for sealing or expungement under current Illinois law.

For help with your case, find a Illinois DUI attorney.