Illinois Property Tax Calculator

Of the 102 Illinois counties with measured ACS 2024 data, 102 carry an effective rate above the 0.92% national average while 0 sit below it.

Worked example: A home at Illinois's median value of $263,300 pays roughly $5,292 a year at the 2.01% state average rate, but about $6,793 at Lake County's 2.58% rate versus $2,528 at Hardin County's 0.96%.

Rates roughly double from Illinois's cheapest county (0.96%) to its most expensive (2.58%).

At the median, a Illinois homeowner's $5,298 annual bill works out to about $442 a month on top of mortgage, insurance, and utilities, one reason the effective rate matters as much as the sticker price when comparing locations.

Reading these numbers correctly matters. An effective rate is a measured outcome, not a posted tax rate: it captures what typical homeowners actually paid after exemptions, assessment ratios, and every overlapping levy settled out. That makes it the most comparable single figure across county lines, where statutory mill rates are defined against different assessment bases and cannot be compared directly. Two counties with identical posted rates can produce very different real bills, and the reverse is just as common. Lenders use a similar logic when they estimate escrow: a percentage of value, calibrated to the taxing jurisdiction. Treat the figures here the same way, as a calibrated starting point that tells you which jurisdictions are expensive relative to home value, and confirm the exact bill with the assessor before you commit.