How is Cook County property tax calculated?

Residential property is assessed at 10% of fair market value. That assessed value is multiplied by a state equalization factor, exemptions are subtracted, and the local composite tax rate is applied to the result to get the annual bill.

What is the effective property tax rate in Chicago?

Chicago's effective rate is roughly 2.08% of fair market value for residential property, though it varies by year as the equalizer and local levies change. The effective rate is the annual tax divided by the home's market value.

What is the homeowner exemption worth?

The general homeowner exemption reduces the equalized assessed value by a fixed amount for an owner-occupied principal residence, lowering the taxable base. This tool subtracts a representative exemption from the equalized value before applying the rate.

What is the state equalizer?

Illinois applies an equalization factor, or multiplier, to Cook County assessed values so that assessments across counties are comparable. The factor is published annually and is applied after the 10% assessment ratio.

Is this an official bill?

No. This is an estimate using representative rates and factors. Your actual bill depends on the assessor's current valuation, the published equalizer, your specific taxing districts, and any additional exemptions you qualify for.

Chicago Property Tax Estimator

Chicago property taxes follow a multi-step Cook County formula rather than a single flat percentage. This estimator walks your home’s market value through the assessment ratio, the state equalizer, exemptions, and the local rate to produce an estimated annual bill and effective rate of around 2.08%.

How it works

The Cook County residential formula is:

assessed value     = market value × 0.10
equalized value    = assessed value × state equalizer
taxable value      = equalized value − exemptions
annual tax         = taxable value × local tax rate
effective rate     = annual tax / market value

The 10% assessment ratio applies to residential property, the equalizer aligns Cook County with the rest of Illinois, and exemptions such as the homeowner exemption shrink the taxable base before the local rate is applied.

Example and tips

A 350,000 dollar Chicago home assesses at 35,000 dollars. After the state equalizer and the homeowner exemption, the taxable equalized value is multiplied by the local rate to yield an annual bill near 7,300 dollars, an effective rate close to 2.08%. Always claim every exemption you qualify for — the homeowner, senior, and senior-freeze exemptions can each meaningfully cut the taxable base.