​​​Equalization Factors

In Kane County, assessed valuations are developed independently in each of our 16 Townships.  However, many of our school districts, municipalities, and other local governments extend across those Township boundaries.  Because of this, the Illinois Property Tax Code requires equalization to provide for an equitable distribution of the property tax burden across township lines.
Generally, the process requires ten steps:

  1. Conduct a three-year sales-ratio study - Prior to the start of the 2019 (payable 2020) taxable year, I conducted a three-year sales-ratio study of real property transactions in each assessment jurisdiction in the County.  In a sales-ratio study, I’m comparing a sale price with the assessed valuation of the property.  For example, a property with a sale price of $100,000 and an assessed value of $30,000 has a ratio of ($30,000 ÷ $100,000) .3000 (i.e., 30.00%).  The Property Tax Code requires that the sales for this study must be from the three prior years.  35 ILCS 200/1-55.
  2. Calculate a three-year level of assessments - So that no single year can produce an outlier and skew a local assessment jurisdiction’s study, a three-year average is used; again, this is required by state law.  35 ILCS 200/1-55.
  3. Calculate a projected equalization factor - The projected equalization factor is the ratio between the current three-year level of assessments and the statutory three-year level of assessments.
  4. Send projected equalization factors to Township Assessor - This provides notice that if no changes are made in their jurisdiction when they certify their assessment rolls, each non-farm property will be increased by that projected equalization factor.
  5. Receive certified assessment rolls from Township Assessor - By statute, each Township Assessor must return their assessment rolls no later than June 15 of the taxable year.
  6. Review assessment roll Each assessment roll is reviewed for changes before a final equalization factor is calculated.
  7. Calculate final equalization factor - As with the projected equalization factor, the final equalization factor is the ratio between the current three-year level of assessments and the statutory three-year level of assessments.
  8. Apply final equalization factor to all non-farm parcels
  9. Publish notice to taxpayers - By state law, the primary notice of the application of an equalization factor is made by publication in a local newspaper.  35 ILCS 200/12-10.This notice also, by state law, is the primary means of notifying taxpayers that they have 30 days to file an assessment complaint with the Board of Review. 35 ILCS 200/16-25. This information is also posted at www.KaneCountyAssessments.org and emailed to person who has signed up to receive Kane Assessment News, Etc.
  10. Repeat in all Townships - This process is repeated in every Township in Kane County.

The final factors are also subject to review by the Illinois Department of Revenue (IDOR), which  conducts an independent equalization study of each county in Illinois, and issues its own equalization factor.  If the correct equalization factor was applied to each of the 16 Townships, the Department will issue an equalization factor of 1.0000, indicating the assessments are at the correct legal level of assessments.  Kane County has received an equalization factor of 1.0000 from the state every year since 1987.

Click here for Understanding Equalization Factors

The current year township equalization factors can be found in the progress report​; historic equalization factors are below.

TownshipS/A 2013S/A 2014S/A 2015S/A 2016S/A 2017S/A 2018
​S/A 2019
St. Charles
Big Rock1.00001.00001.00001.01651.00001.0574​1.0373
Sugar Grove0.95040.98961.04581.07481.04611.0471​1.0403