Chicago has one of the highest combined sales tax rates in the United States, because four layers of tax stack on the same purchase: the State of Illinois, Cook County, the City of Chicago and the regional transit authority.
This guide shows each layer with its source, the date the table applies from, a worked example that is our own arithmetic, and what the sources say about groceries, medicine and the separate Chicago Restaurant Tax. Local rates can change on 1 January and 1 July, and the transit rate changed on 1 August 2026, so check the official rate finder before relying on any figure.
The table is our own addition of four components. Each component comes from the source named in the last column. The date is the effective date of the most recent change, the transit increase.
| Layer | Rate | Source |
|---|---|---|
| State of Illinois | 6.25% | City of Chicago glossary (state Retailers' Occupation Tax) |
| Cook County home rule sales taxes | 1.75% | Cook County official statement, September 2026 |
| City of Chicago home rule tax | 1.25% | City of Chicago glossary |
| Northern Illinois Transit Authority (formerly RTA) | 1.25% | Illinois Department of Revenue bulletin FY 2026-34, effective 1 August 2026 |
| Combined (our sum) | 10.50% | Calculated by CountryTaxCalc.com |
The Illinois Department of Revenue says: "Effective August 1, 2026, the NITA (formerly the Regional Transportation Authority) occupation and use tax rate will increase by 0.25% in Cook, DuPage, Kane, Lake, McHenry, and Will counties." The new Cook County rate is 1.25%, so the earlier rate was 1.00% by our subtraction, which gives 10.25% for the period before August 2026 (our calculation).
The Northern Illinois Transit Authority replaced the Regional Transportation Authority. A Cook County official statement describes the Northern Illinois Transit Authority Act as generally effective June 1, 2026. The Department of Revenue bulletin FY 2026-34 (June 2026) sets the new Cook County transit rate at 1.25% for general merchandise and 1.50% for qualifying grocery and qualifying drugs and medical appliances.
The bulletin says these transit rates "are added to the statewide rate (6.25% or 1.00%) plus any local taxes collected by IDOR." We have not found an official Chicago combined rate for groceries and medicine, so this page does not give one.
For general merchandise at the 10.50% combined rate, tax is the price times 0.105. These are our own calculations, not official figures.
| Purchase price | Tax at 10.50% | Total | Tax at 10.25% (before Aug 2026) |
|---|---|---|---|
| $100 | $10.50 | $110.50 | $10.25 |
| $1,000 | $105.00 | $1,105.00 | $102.50 |
| $2,500 | $262.50 | $2,762.50 | $256.25 |
The 0.25 point increase adds $2.50 for every $1,000 of taxable purchases.
The City of Chicago glossary says the city's 1.25% tax applies to retail sales of tangible personal property other than property titled or registered with the State, and that "Grocery food and prescription and nonprescription medicines are generally exempt from the tax."
The state side changed on 1 January 2026. The Department of Revenue says Illinois eliminated its 1% sales and use tax on groceries, while the 1% state rate continues on qualifying drugs and medical appliances. The transit tax on grocery food has not been eliminated: the Department of Revenue lists a Cook County transit rate of 1.50% for qualifying grocery and qualifying drugs and medical appliances from 1 August 2026. Municipalities and counties may add a 1% local grocery tax by ordinance; the Department's May 2026 bulletin lists no Chicago or Cook County entry, but check the rate finder for your address, because we have not found an official Chicago combined rate for groceries or medicine.
For items that must be titled or registered, the Department of Revenue lists a Cook County transit rate of 1.25% from 1 August 2026, and the city glossary lists a 1.25% Chicago use tax on titled property purchased from a retailer outside the city and registered there.
The City of Chicago Department of Finance lists a separate Restaurant Tax. It says: "The tax is imposed on the selling price of all food and beverages sold at retail by the place for eating." Sales exempt from the Illinois Retailers' Occupation Tax are also exempt from it. Check the Department of Finance page for the current rate.
The Department of Revenue also notes that local governments may impose taxes and fees it does not collect, so ask the city or county about anything not shown by the rate finder.
The Department of Revenue directs businesses to the MyTax Illinois Tax Rate Finder at mytax.illinois.gov, where you select the month. Municipal and other local layers vary, so an address just outside the city limits can be taxed differently from a Chicago address.