An equitable assessment of a parcel's value is one important part of the process to establish the appropriate real estate tax on a piece of property. For tax purposes, the value of each property on January 1st of the taxable year is used. The assessors use a numerical equalization formula to make sure all properties within the county are uniformly assessed at 1/3 of the fair market value. That amount becomes the property's taxable value, except in situations where that property holder is eligible for credits or exemptions*. In that circumstance those amounts are subtracted from the assessed value, which then establishes a new and lower taxable value.
The other and equally important part of the determination of a property's real estate tax is the tax rate. Tax rates vary among the 237 tax code districts within the county, since each parcel of property lies within the boundaries of several taxing bodies. Tax rates are calculated by the Tax Extension Division of the County Clerk's office for each individual taxing district. This is accomplished by dividing the amount of money (the levy) that the taxing units of local government (school, forest preserve, township, county, etc.) budget to raise from property taxes, by the tax base for that jurisdiction. All of these determinations are of course subject to legal limits.
With the taxable value of each property established, and the tax rate determined through the actions of the many taxing bodies, it becomes possible to calculate the real estate property tax on all of the 150,000 parcels. The tax rate is multiplied against the taxable value of each parcel of real estate to arrive at the property tax. To calculate the exact dollar and cents amount of the tax, or to check the accuracy of your tax bill, you must remember to move the decimal point of the tax rate two places to the left, since the rate is based on hundreds.
*Owner Occupied Exemption, Senior Citizen Homestead Exemption, Senior Citizen Freeze, Homestead Improvement Exemption, Disabled Veteran Exemption and 4 others Note: In general, properties owned by the US Government, State of Illinois, Winnebago County, Municipalities, School Districts, Churches and 501(c)(2) and 501(c)(3) Charitable Organizations are exempt from payment of property taxes.