This morning I received an email from a gentleman considering relocating to Naperville. He asked for help understanding property tax rates there since Naperville is in both DuPage and Will counties.
Tax rates in the Chicago area are usually described in terms of an amount per $100 of value by governments (e.g. $7.5 per $100 of value or 7.5% of value), so it’s important to understand what is meant by value. Value is assessed value. In all Illinois counties except Cook County, property is assessed at 1/3 of fair market value. So a home with a fair market value of $400,000 has an assessed value of $133,333.33 ($400,000 / 3). Cook County assessed values range from 16% to 38% of fair market value depending on how the property is classified.
If you stop by the sales office of a new home development (don’t forget to take your Realtor with you! ;)) and ask what the estimated taxes will be for a new home, the sales staff usually puts the tax rate in terms of a rate to be multiplied against the sales price of a home. Since the sales price is often considered the fair market value, the rate will be around 1/3 of the rate stated by a government agency. So if a county website says the average tax rate for the county is $7.5 per hundred dollars of value, a builder’s sales rep will probably say that the rate is 2.5% ($2.5 per hundred dollars of sale price, 1/3 of $7.5).
According to the Office of the Will County Clerk, the 2005 average Will County property tax rate was $7.3103 per hundred dollars of value. To estimate the taxes for a $400,000 home multiply the assessed value by the tax rate (($400,000 x 1/3) x ($7.3103 / 100)) for taxes of $9,747.06. Another way to arrive at the same answer is to multiply the price of the home by 1/3 of the tax rate ($400,000 * (0.073103 /3)) = $9,747.06.
In DuPage County, property tax rates vary widely between suburbs with 2005 taxes rates ranging from $8.2058 for Glendale Heights down to $2.7896 for Oak Brook. The part of Naperville in DuPage County had a 2005 tax rate of $5.7984. The DuPage County Clerk has a list of 2005 taxes rates by community. To estimate the taxes for a suburb in DuPage County, use the same formulas as above with the tax rate for that suburb.
Fran Bailey specializes in downtown Chicago, Lincoln Park and Lake View condos, co-op apartments and houses. She has shared home buying and selling advice since 2006 and written about over 130 Chicago high rises. To schedule showings for any listings, get a 
