Skip to main content
Sign Up For Updates

2023 Cook County Tentative Multiplier Announced

Press Release - Thursday, February 08, 2024

SPRINGFIELD, IL - A tentative 2023 property tax equalization factor of 2.8414 for Cook County was announced today by the Illinois Department of Revenue.

The Department is required by law to calculate the factor, often called the multiplier, to achieve uniform property assessment throughout the state.

The 2023 tentative equalization factor decreased from the 2022 final factor of 2.9237.

The department determines the equalization factor for each county by comparing a three-year period the actual selling price of individual properties to the assessed value placed on those properties by the county assessor. If the median level of assessment for all property in the county varies from the 33 1/3 percent level required by law, an equalization factor is assigned to bring assessments to the legally mandated level.

The three-year average level of assessments (weighted by class) for Cook County property is 11.73 percent. The department calculated the multiplier to bring the average level of assessments to the required 33 1/3 percent level by dividing Cook County's three-year average of 11.73 into 33.33.

After taking into account the 2023 reassessments, the levels of assessment are as follows:

                                                                                             3-Year
                   Class                   2020       2021      2022       Average

1            (Vacant Lots)             7.62       7.93       6.80          7.45
2            (Residential)              9.94       9.13       8.23          9.10
3            (Apartments)             9.04        7.75      7.09          7.96
5a          (Commercial)            28.69     27.53    24.09         26.77
5b          (Industrial)                29.22      27.49    21.30        26.00

COUNTYWIDE
(Weighted average)                12.82     11.81     10.56        11.73


The equalization factor does not cause individual tax bills to go up. Tax bills are determined by local taxing bodies when they request the dollars needed to provide services to citizens. The assessment process simply determines how the bill will be divided among taxpayers.

A Cook County ordinance requires that residential property (homes, condominiums, apartment buildings of six units or less) be assessed at 10 percent of market value; all other residential property (apartments with more than six units), 10 percent; vacant lots, 10 percent; property owned by not-for-profit corporations, 25 percent; commercial property, 25 percent; industrial property, 25 percent; and commercial or industrial property being developed in economically deprived areas, usually 10 percent.