Illinois property guide

Illinois Property Tax Calculator

Estimate a property tax bill from assessed value, exemptions and local rates. Illinois rules and editable local assumptions are applied below.

By Calculate My Property EditorialUpdated September 30, 2026Professional review pending
01 / Your inputs

Start with your property.

County names: Census 2025. Enter your parcel’s millage below; county rates are awaiting verification.
Property2 inputs
USD
Assessment5 inputs
%
Applied only when no certified taxable value is entered.
USD
Zero estimates a newly assessed property.
USD
Enter a confirmed local exemption, after assessment conversion.
Local rates4 inputs
mills
Illustrative assumption. Replace with the parcel’s effective school millage.
mills
Illustrative county/city/district assumption, not a verified county rate.
USD / year
Special assessments and fixed charges, added after tax caps.
USD / year
Only relief deducted from this bill. Do not enter a later refund or a value exemption here.
All amounts in USD.
Your estimate

Estimated annual property tax

$6,300Based on your inputs · USD
Monthly equivalent
$525
Assessed / taxable scenario
$350,000
Effective rate on value
1.8%
See the breakdown
School taxable base
$350,000
Other taxable base
$350,000
School levy
$2,100
Other levies
$4,200
Tax after bill cap
$6,300
Approved tax-dollar credit applied
$0
Fixed / special charges
$0
The formula

Taxable bases × applicable millage ÷ 1,000 − approved bill credits + fixed charges

Assumptions & limitations (1)
  • Local millage is a user assumption until replaced with the parcel’s certified rates. County names do not establish a parcel tax rate.
02 / Your next decisionTransfer TaxSeller Net Sheet
External resource

Considering a property-tax appeal?

Compare service terms, fees and state coverage with your assessment notice.

Explore OwnwellExternal provider or resource. No paid referral arrangement is active.
Planning estimate. Editorially sourced; independent professional review is pending. How we calculate
The Illinois details

How this state changes the estimate

Assessment and taxable value

Illinois uses equalized assessed value and overlapping local levies. Assessment classification differs in Cook County, and the equalization factor can change the taxable base. Enter equalized taxable value directly; the model does not pretend there is a single statewide market-value ratio.

The default assessment conversion is 100.0% where the state uses a uniform ratio. A certified assessed value takes precedence. Do not substitute a county-wide average for a parcel’s taxing-district rates.

Exemptions and caps

General homestead, senior and other exemptions affect eligible equalized assessed value. Obtain the exemption amounts from the actual assessment record, especially for Cook County.

Confirm eligibility using the primary source and local office. A purchase, property classification, tenancy type or exemption can change which rule applies. Enter documented local costs and rates rather than carrying a previous owner’s assumptions into the new deal.

Your bill calendar

County installment schedules differ. Cook County and other counties do not necessarily bill on the same dates or use the same first-installment calculation.

Independent professional review is pending. Current county millage is not yet published in this data set. Use the assessor’s certified taxable value and the tax collector’s current rates.

Illinois county directory & rate status

County equivalents are from the 2025 US Census Gazetteer. Millage is pending source verification; no county tax rate has been invented.

County / local equivalentCounty identifierRate status
Adams County17001Enter parcel’s certified rate
Alexander County17003Enter parcel’s certified rate
Bond County17005Enter parcel’s certified rate
Boone County17007Enter parcel’s certified rate
Brown County17009Enter parcel’s certified rate
Bureau County17011Enter parcel’s certified rate
Calhoun County17013Enter parcel’s certified rate
Carroll County17015Enter parcel’s certified rate
Cass County17017Enter parcel’s certified rate
Champaign County17019Enter parcel’s certified rate
Christian County17021Enter parcel’s certified rate
Clark County17023Enter parcel’s certified rate
Clay County17025Enter parcel’s certified rate
Clinton County17027Enter parcel’s certified rate
Coles County17029Enter parcel’s certified rate
Cook County17031Enter parcel’s certified rate
Crawford County17033Enter parcel’s certified rate
Cumberland County17035Enter parcel’s certified rate
DeKalb County17037Enter parcel’s certified rate
De Witt County17039Enter parcel’s certified rate
Douglas County17041Enter parcel’s certified rate
DuPage County17043Enter parcel’s certified rate
Edgar County17045Enter parcel’s certified rate
Edwards County17047Enter parcel’s certified rate
Effingham County17049Enter parcel’s certified rate
Fayette County17051Enter parcel’s certified rate
Ford County17053Enter parcel’s certified rate
Franklin County17055Enter parcel’s certified rate
Fulton County17057Enter parcel’s certified rate
Gallatin County17059Enter parcel’s certified rate
Greene County17061Enter parcel’s certified rate
Grundy County17063Enter parcel’s certified rate
Hamilton County17065Enter parcel’s certified rate
Hancock County17067Enter parcel’s certified rate
Hardin County17069Enter parcel’s certified rate
Henderson County17071Enter parcel’s certified rate
Henry County17073Enter parcel’s certified rate
Iroquois County17075Enter parcel’s certified rate
Jackson County17077Enter parcel’s certified rate
Jasper County17079Enter parcel’s certified rate
Jefferson County17081Enter parcel’s certified rate
Jersey County17083Enter parcel’s certified rate
Jo Daviess County17085Enter parcel’s certified rate
Johnson County17087Enter parcel’s certified rate
Kane County17089Enter parcel’s certified rate
Kankakee County17091Enter parcel’s certified rate
Kendall County17093Enter parcel’s certified rate
Knox County17095Enter parcel’s certified rate
Lake County17097Enter parcel’s certified rate
LaSalle County17099Enter parcel’s certified rate
Lawrence County17101Enter parcel’s certified rate
Lee County17103Enter parcel’s certified rate
Livingston County17105Enter parcel’s certified rate
Logan County17107Enter parcel’s certified rate
McDonough County17109Enter parcel’s certified rate
McHenry County17111Enter parcel’s certified rate
McLean County17113Enter parcel’s certified rate
Macon County17115Enter parcel’s certified rate
Macoupin County17117Enter parcel’s certified rate
Madison County17119Enter parcel’s certified rate
Marion County17121Enter parcel’s certified rate
Marshall County17123Enter parcel’s certified rate
Mason County17125Enter parcel’s certified rate
Massac County17127Enter parcel’s certified rate
Menard County17129Enter parcel’s certified rate
Mercer County17131Enter parcel’s certified rate
Monroe County17133Enter parcel’s certified rate
Montgomery County17135Enter parcel’s certified rate
Morgan County17137Enter parcel’s certified rate
Moultrie County17139Enter parcel’s certified rate
Ogle County17141Enter parcel’s certified rate
Peoria County17143Enter parcel’s certified rate
Perry County17145Enter parcel’s certified rate
Piatt County17147Enter parcel’s certified rate
Pike County17149Enter parcel’s certified rate
Pope County17151Enter parcel’s certified rate
Pulaski County17153Enter parcel’s certified rate
Putnam County17155Enter parcel’s certified rate
Randolph County17157Enter parcel’s certified rate
Richland County17159Enter parcel’s certified rate
Rock Island County17161Enter parcel’s certified rate
St. Clair County17163Enter parcel’s certified rate
Saline County17165Enter parcel’s certified rate
Sangamon County17167Enter parcel’s certified rate
Schuyler County17169Enter parcel’s certified rate
Scott County17171Enter parcel’s certified rate
Shelby County17173Enter parcel’s certified rate
Stark County17175Enter parcel’s certified rate
Stephenson County17177Enter parcel’s certified rate
Tazewell County17179Enter parcel’s certified rate
Union County17181Enter parcel’s certified rate
Vermilion County17183Enter parcel’s certified rate
Wabash County17185Enter parcel’s certified rate
Warren County17187Enter parcel’s certified rate
Washington County17189Enter parcel’s certified rate
Wayne County17191Enter parcel’s certified rate
White County17193Enter parcel’s certified rate
Whiteside County17195Enter parcel’s certified rate
Will County17197Enter parcel’s certified rate
Williamson County17199Enter parcel’s certified rate
Winnebago County17201Enter parcel’s certified rate
Woodford County17203Enter parcel’s certified rate
Download the state source record (JSON)
Worked example

Follow the default numbers.

With market / assessed value of $350,000, the model gives estimated annual property tax: $6,300.

The formula is taxable bases × applicable millage ÷ 1,000 − approved bill credits + fixed charges. Open the breakdown to trace expenses and assumptions. Change one input at a time to see how your decision changes. This example uses scenario inputs; it is not an offer, tax bill, appraisal or legal determination.

A housing-value example for Illinois

Census QuickFacts reports a median owner-occupied home value of $263,300 for 2020–2024. This is a dated housing estimate, not a current sale-price median or a parcel assessment. The source was checked on 2026-09-30.

Assume the parcel record shows $80,000 of taxable equalized assessed value after its approved exemptions. At an assumed combined 75 mills, the annual estimate is $6,000. The $263,300 market-value median is not converted to that base by this tool. Cook County classification, local assessments and the applicable equalization factor must come from the assessment record. Once exemptions are reflected in taxable EAV, leave the generic value deduction at zero. A rate quoted as 7.5% of EAV equals 75 mills.

The live model gives $6,000 under these assumptions. Local rates and any illustrative certified bases in this scenario are hypothetical. Replace them with the parcel’s matching tax-year records before budgeting a bill.

Load this example in the calculator

Start with the assessor’s taxable value

Market value, assessed value and taxable value are not interchangeable. A certified taxable-value override is the safest input when you have the current parcel record. Without it, the calculator applies the selected state’s simplified assessment model to the entered value. School and other millage are applied separately where exemptions differ. A mill is one dollar per thousand dollars of taxable value.

A county is not one tax district

School, city, special-district and bond levies can differ within the same county. The county selector identifies the jurisdiction; it does not imply a single county-wide bill rate. The sample millages are clearly labeled assumptions. Replace them with the effective levies for the parcel and tax year, then add non-ad-valorem charges separately.

A purchase can reset the assessment

Existing-owner assessment caps may not transfer to a buyer. Michigan taxable value can uncap after a transfer; California can re-establish a base value; Florida’s Save Our Homes benefit has transfer and portability conditions. Select a reassessment reset when modeling a new purchase unless the assessor confirms another treatment. A seller’s current bill can substantially understate the buyer’s tax expense.

Tax relief needs eligibility

Homestead status, age, disability and veteran exemptions depend on state and local rules. Only the basic modeled homestead treatment is automatic. Other exemptions are a manually confirmed taxable-value adjustment. Credits, levy-specific deductions, tax freezes and appeal relief can require a different calculation. The state notes and official source links explain what to check before using the result in a rental or net sheet.

Keep your assumptions with the result

Save the calculation to your deal file to reuse compatible inputs in another tool. The file stays in this browser on this device. Download the CSV to open the complete inputs, results and schedule in Excel or Google Sheets. Use PDF to print the report or save it as a PDF. A share link includes entered financial figures in its URL, so use it only with people you intend to share those numbers with.