Illinois Reverse Sales Tax Calculator
Illinois has a 6.25% state sales tax on most goods, but Chicago is where things get complicated. Chicago's combined rate is 10.25% — one of the highest in any major US city — stacking state, Cook County, City of Chicago, Regional Transportation Authority (RTA), and Metro Pier and Exposition Authority (MPEA) levies. If you're processing receipts from Chicago, you need to use 10.25%, not the statewide average.
Outside Chicago, the picture is simpler. Most cities in the collar counties and downstate Illinois fall in the 8–9% range. The statewide average is around 8.82%. For Springfield, use 8.50%. For Joliet (Will County), around 9.75%. For Naperville, 8.75%. The calculator defaults to the statewide average of 8.82% — adjust it to your specific city for precise results.
Current Illinois Sales Tax Rates
| Component | Rate |
|---|---|
| State rate | 6.25% |
| Average local rate | 2.57% |
| Average combined rate | 8.82% |
| Location | Combined Rate |
|---|---|
| Chicago | 10.25% |
| Aurora | 8.25% |
| Naperville | 8.75% |
| Joliet | 9.75% |
| Springfield | 8.50% |
What's Taxable in Illinois
Illinois has an unusually low rate on groceries. Food for home consumption is taxed at just 1% state rate (not the full 6.25%), making Illinois one of the few states that taxes groceries at all, but at a heavily reduced rate. Prescription drugs and medical appliances are exempt. Restaurant meals and prepared food are taxable at the full combined rate. Illinois also taxes some services, including certain repair and maintenance services.
Worked Example
You bought electronics in Chicago. Total on the receipt: $278.43 at Chicago's combined rate of 10.25%.
$278.43 ÷ 1.1025 = $252.57 (pre-tax price)
$278.43 − $252.57 = $25.86 (tax amount)
That's $25.86 in sales tax on a $252.57 purchase before tax. The main calculator handles this automatically — enter the total and your rate, and the pre-tax price and tax amount appear instantly.
Frequently Asked Questions
Chicago's combined sales tax rate is 10.25% — made up of 6.25% Illinois state, 1.75% Cook County, 1.25% City of Chicago, 1.0% Regional Transportation Authority (RTA), and 0.25% Metro Pier and Exposition Authority (MPEA). For any Chicago purchase, divide your total by 1.1025 to find the pre-tax price.
Yes, but at a heavily reduced rate. Unprepared food for home consumption is taxed at 1% state rate rather than the full 6.25%. Local taxes may also apply on top of the 1% state portion. Prescription drugs are fully exempt. Restaurant meals and prepared food are taxed at the full combined rate. Illinois temporarily reduced the grocery rate to 0% in 2022–2023 but it has since returned to 1%.
Divide your total by (1 + rate as a decimal). For Chicago at 10.25%: $278.43 ÷ 1.1025 = $252.57 pre-tax. Tax = $278.43 − $252.57 = $25.86. For the statewide average of 8.82%, divide by 1.0882. For Springfield at 8.50%, divide by 1.085. Always check your receipt for the exact rate when processing expense reports.
Chicago's 10.25% rate results from multiple government layers each adding their own levies: Illinois state (6.25%), Cook County (1.75%), City of Chicago (1.25%), the Regional Transportation Authority (1.0%), and the Metro Pier and Exposition Authority (0.25%). Each layer funds different services. Chicago also levies separate taxes on specific items like restaurant food and alcohol that push the effective rate even higher on those purchases.