Illinois Sales Tax Calculator (2026) — Add or Reverse Tax
Illinois's combined sales tax rate is 8.96% (6.25% state + 2.71% average local). Use the calculator below to add Illinois sales tax to a price, or reverse a tax-included total to find the pre-tax price and exact tax amount.
How to use this calculator:
- Adding tax — enter a pre-tax price, pick "Add tax to price," and the calculator applies the Illinois rate to show the tax amount and final total.
- Reversing (extracting) tax — enter a total that already includes tax, pick "Extract tax from total," and the calculator divides by 1 + the rate to isolate the pre-tax price and the exact tax paid.
- Pick the rate that matches your situation: the average combined rate is a good statewide estimate, but the state-only or maximum-local rate is more precise if you know the exact city or county.
Understanding Illinois Sales Tax
Illinois's state sales tax rate is 6.25%, and local jurisdictions add an average of 2.71% on top, bringing the typical combined rate to 8.96%. Rates vary by city and county — the highest combined rate in Illinois can reach 11.00%.
Illinois eliminated its 1% statewide grocery tax effective January 1, 2026, and removed its 200-transaction nexus test the same year.
Illinois also levies a state income tax, which shapes how much the state relies on sales tax revenue relative to other funding sources.
Groceries
Exempt from Illinois state sales tax.
Largest city
Chicago
State income tax
Yes
Why Reverse Sales Tax Calculation Matters
Receipts, invoices, and marketplace payouts usually show only the tax-included total — not the pre-tax price. Reversing the calculation matters for bookkeeping (separating revenue from tax collected), expense reports (reimbursing only the pre-tax cost), and price comparisons (checking what an item actually costs before Illinois's tax is applied). Because dividing by (1 + rate) is not the same as simply subtracting the rate from the total, doing this by hand is a common source of errors — the calculator above handles it exactly.
Illinois Taxability at a Glance
🛒 Groceries
Exempt
👕 Clothing
Taxable
💊 Prescription drugs
Exempt
History & Rate Breakdown
Illinois enacted its Retailers' Occupation Tax (ROT) — its legal name for what functions as a sales tax — on June 28, 1933. Chicago added its own home-rule sales tax in 1981, and Cook County followed with a county-level tax in 1992.
Illinois's 8.96% average combined rate stacks the 6.25% state ROT with home-rule city and county taxes. Chicago's own base rate is 3% on top of Cook County's 3%, and layered with special business-district taxes, some Chicago-area purchases reach a combined rate as high as 11.5% — among the highest in the country for a major US city.
Where the Money Goes
Illinois's home-rule structure (Chicago and other large municipalities can set their own ROT rate without state legislative approval) means local sales tax revenue in the Chicago area is a significant, independently-controlled funding source for city and county government, separate from the state's own budget.
Business Use Case: Registering & Collecting Illinois Sales Tax
As of a 2025 sourcing change, a remote seller shipping into Illinois now charges destination-based ROT — the combined state and local rate for the buyer's delivery address — rather than a single statewide rate, meaning a shipment to a Chicago address and one to a rural downstate address can carry very different tax rates from the same seller.
Sales Tax Terms Glossary
Combined rate
The state sales tax rate plus any applicable local (city, county, or special district) rates — the actual rate charged at checkout in a given location.
Reverse sales tax
The process of working backward from a tax-included total to find the pre-tax price and the exact tax amount, using total ÷ (1 + rate) = pre-tax price.
Economic nexus
A sales threshold (in dollars, transaction count, or both) that obligates an out-of-state seller to collect and remit sales tax even without a physical presence in the state.
Marketplace facilitator
A platform (e.g. Amazon, Etsy, eBay) that collects and remits sales tax on behalf of third-party sellers under most states’ marketplace facilitator laws.
Real-World Example
A $500.00 purchase in Illinois at the average combined rate of 8.96%:
- Tax amount: $500.00 × 8.96% = $44.80
- Total price: $500.00 + $44.80 = $544.80
Illinois Sales Tax Compliance for Sellers
Remote and online sellers establish economic nexus in Illinois once they exceed $100,000.00 in annual sales (no separate transaction-count test). Once nexus is established, a seller must register with the state, collect Illinois sales tax at checkout, and file returns on the state's required schedule. Marketplace facilitators (Amazon, Etsy, eBay, Walmart) generally collect and remit on behalf of third-party sellers automatically.
Frequently Asked Questions — Illinois Sales Tax
What is the sales tax rate in Illinois?▾
Does Illinois tax groceries?▾
Does Illinois have a state income tax?▾
When do online sellers need to collect Illinois sales tax?▾
How do I calculate Illinois sales tax on a purchase?▾
How do I reverse Illinois sales tax to find the price before tax?▾
What is the formula to back out sales tax from a receipt in Illinois?▾
References & Sources
Rates last verified January 2026. Illinois sales tax rates and thresholds can change — always confirm current figures with the Illinois Department of Revenue before filing or invoicing. This tool is for estimation and educational purposes only and is not tax, legal, or accounting advice.
Jordan Hayes
Verified AuthorLead Content Editor & Personal Finance Specialist
Jordan Hayes is a personal finance content strategist with 9+ years building educational finance and health resources. He has written and fact-checked over 200 personal finance guides covering mortgage amortization, retirement planning, tax strategy, and budgeting. His work applies IRS publications, Federal Reserve data, and peer-reviewed research to make complex calculations accessible.