DeKalb County has received a final property assessment equalization factor of 1.0000 for the 2025 tax year, according to David Harris, director of the Illinois Department of Revenue (IDOR). The equalization factor, also known as the “multiplier,” is used to ensure that property assessments are uniform across counties in Illinois. This process is important because many local taxing districts, such as school and fire protection districts, cross county lines.
Under state law enacted in 1975, most property in Illinois should be assessed at one-third of its market value. Farm properties are treated differently; farm homesites and dwellings follow regular assessment procedures, while farmland itself is assessed at one-third of its agricultural economic value and does not use the state equalization factor.
For DeKalb County, assessments were found to be at 33.37% of market value based on sales data from 2022 through 2024. The newly assigned multiplier applies to taxes payable in 2026. Last year’s multiplier for DeKalb County was also set at 1.0000.
The announcement follows a public hearing on the tentative factor issued on November 6, 2025, which was also set at 1.0000. The annual determination of the equalization factor involves comparing recent sale prices with assessed values over a three-year period.
According to IDOR: “If the three-year average level of assessment is one-third of the market value, the equalization factor will be one (1). If the average level of assessment is greater than one-third of market value, the equalization factor will be less than one (1). And if the average level of assessment is less than one-third of market value, the equalization factor will be greater than one (1).”
A change in this multiplier does not directly affect total property tax bills. Tax bills depend on how much money local taxing bodies request each year for services provided to residents. If those requests do not increase compared to previous years, overall property taxes remain unchanged even if assessments rise.
The share each taxpayer pays depends on their individual property’s assessed value; this share does not change due to application of the multiplier.
The Illinois Department of Revenue manages state taxation and revenue collection responsibilities and aims to administer tax laws fairly while providing timely information and fostering diversity and equity within its operations (official website, official site).
