The three lowest composite tax rates in Cook County belong to Hinsdale (about 6.5%), Burr Ridge (6.8%) and Barrington (7.2%). Those are three of the most expensive towns in the region, and Hinsdale's median tax bill — roughly $14,400 a year — is the highest in DuPage County.
That isn't a contradiction. It's the answer to the question, and it's why the question needs rephrasing before it can help you.
On this page: Rate and Bill Are Different Questions · Why a Cook Rate and a DuPage Rate Don't Compare · What the Effective Rates Look Like · The Town Average Will Be Wrong for Your House · What Raises Your Bill · Reassessment Timing Is the Buyer's Trap · Two Claims That Don't Hold · How to Check Your Own Number
Rate and Bill Are Different Questions
A tax rate is applied to your home's value. A low rate on an expensive house produces a large bill. A high rate on a cheap house produces a small one.
And towns with low rates usually have them because property there is expensive. The schools and the village need a certain number of dollars. Spread that levy across more assessed value and the rate per dollar falls. Cheap towns run high rates for the same reason in reverse.
So decide which question you're asking:
- "Where is my annual bill smallest?" Generally the less expensive south and far-west suburbs, where you'll pay a higher rate on a lower value. The cheapest suburbs to buy in runs that trade town by town, on carrying cost.
- "Where do I get the most house per tax dollar?" The low-rate towns — and the entry price is the barrier.
Anyone handing you one ranked list of "lowest property taxes" without saying which question it answers isn't helping you.
Why a Cook Rate and a DuPage Rate Don't Compare
This mechanical detail produces most of the confused advice online.
Cook County assesses residential property — houses and condo buildings of six units or fewer — at 10% of market value by county ordinance. State law requires a county-wide level of 33⅓%, so the Illinois Department of Revenue applies an equalization multiplier. The final 2025 Cook multiplier is 3.0300, which puts equalized assessed value near 30% of market before exemptions.
The collar counties — DuPage, Lake, Will, Kane, McHenry — assess at 33⅓% directly, no multiplier.
The consequence: a composite rate in Cook and a composite rate in DuPage are computed against different bases. Someone telling you Oak Park is at 11% and Naperville is at 6% has told you nothing about which is more expensive.
The only number that crosses county lines is the effective rate — tax paid as a share of the house's market value.
Compare effective rates or don't compare. On that basis most of the region sits in a narrower band than the headline rates suggest, roughly 2 to 3%.
What the Effective Rates Look Like
| Place | Effective rate | Basis |
|---|---|---|
| Naperville | ~2.0% | Q4 2025 |
| Naperville 60563 | 2.03% | median, by ZIP |
| Evanston | ~2.06% | Civic Federation, TY2022 |
| Hinsdale | ~2.2% | Q4 2025 |
| Naperville 60564 | 2.23% | median, by ZIP |
| Oak Park | ~2.89% | Civic Federation, TY2022 |
Two of those numbers deserve a second look.
Oak Park is the outlier, and it's structural. Its composite rate runs about 35% above Evanston's. Roughly half the gap is K–12 — Oak Park levies through District 97 and OPRF District 200 at a combined rate far above Evanston's D65 and ETHS. The rest is that Oak Park funds a full township, a separate park district and a community college district that Evanston either lacks or runs in-house. Oak Park levies through 13 taxing bodies; Evanston through 9. There's no single villain — just a longer list of taxing bodies.
Chicago's effective rate is lower than many of the suburbs people move to in order to escape it. Surprising until you remember the city spreads its levy across an enormous commercial base.
The Town Average Will Be Wrong for Your House
Inside Naperville alone, the 60564 ZIP carries a median effective rate of 2.23% while 60563 carries 2.03%. On a $700,000 house that's about $1,400 a year, for a boundary that appears on no map you'll be shown at a showing.
Naperville also sits in two counties — mostly DuPage, partly Will. Your address says Naperville either way. Your bill doesn't.
School district lines, special service areas and library districts all cut across municipal boundaries. A town-level number averages parcels that are taxed differently from each other, which makes it fine for ranking towns and useless for predicting your bill. Arlington Heights is the clearest case: five K–8 districts and two high school districts inside one village, against one of each in Palatine next door.
What Raises Your Bill
Illinois property taxes are levy-driven, not rate-driven, and most people have this backwards. Your assessment rising does not by itself raise your bill. Your bill rises when the taxing districts ask for more money.
In practice: if every house in town gains 20% in assessed value and the levy doesn't change, the rate falls and bills stay roughly flat. You pay more only if your assessment rose more than your neighbors', or the districts asked for more.
Which is why the useful question at a board meeting is never "what's the rate." It's "what's the levy."
Indian Prairie District 204 is a live example. The bonds that built Metea Valley High School are paid off at the end of 2026, and ordinarily the school portion of the rate would fall. It won't — voters approved $420 million in new bonds in November 2024, holding the rate roughly flat. Fair vote, and the money is going into 33 buildings. But a buyer expecting relief in 2027 gets none.
Takeaway: watch the levy and the referendums, not the assessment notice.
Reassessment Timing Is the Buyer's Trap
Cook County reassesses on a three-year cycle by area, and which year your township was last reassessed decides whether the listing's tax figure is real or stale.
- Evanston Township: reassessed for tax year 2025. Notices went out April 2025, residential up about 23% — and that increase hasn't reached a bill yet. It arrives with the second-installment bill, which ran about two months late this year: the county posted the bills online August 18, with paper copies mailing September 1 and payment due October 1. If a seller hands you the tax year 2024 bill, it was settled before the reassessment reached it — the tax year 2025 second installment is the first bill carrying the increase.
- Oak Park Township: reassessed for tax year 2026. Notices went out May 2026, median assessed value up about 25% — and none of it hits bills until summer 2027. An Oak Park buyer in 2026 is reading a tax figure that hasn't absorbed a 25% increase yet.
Two towns, four miles apart, and both listing figures still predate the increase — Evanston's by one delayed bill, Oak Park's by a full year.
One more wrinkle, because it cuts both ways: after Oak Park's 2023 reassessment, about a third of homeowners saw their assessments cut while roughly 40% saw double-digit increases. A township median says very little about one house.
In a just-reassessed township the listing's figure is a countdown measured in months. In one awaiting reassessment, it's measured in years.
Two Claims That Don't Hold
You'll read that Evanston's property tax rates are two points higher than any other municipality in Cook County. The County Clerk's own rate report contradicts it. Evanston is expensive, not an outlier, and it's meaningfully cheaper than Oak Park next door.
You'll also read that Northwestern's tax exemption explains Evanston's bills. The exemption is real, but Evanston's rate is the lower of the Evanston/Oak Park pair despite it, and a 2017 city analysis put the yield from taxing the university at roughly $5.9 million a year — a figure its own author called "a very simple analysis." Worth debating. Not the reason your bill is what it is.
How to Check Your Own Number
Skip the town averages and the estimator widgets.
1. Look up the specific parcel through the county treasurer or assessor. Every county here publishes bills by PIN. 2. Get the most recent bill, not the last full year — especially in a township that was just reassessed. 3. Check which exemptions the current owner has. The homeowner and senior exemptions travel with the person, not the house, and a senior freeze coming off can move a bill by thousands while the listing still shows the frozen number. 4. Ask what's on the ballot. A pending referendum is a levy increase with a date on it.
If the parcel is in Cook County, the Cook County property tax bill guide carries the rest of it: due dates, every exemption and whether it renews itself, and the appeal windows open right now.
To put a number on any of this, the property tax estimator runs a home value against a town's effective rate and shows the gap between two towns.
Rate figures come from the Cook County Clerk's rate reports, the Civic Federation's effective-rate series, and Q4 2025 effective-rate data. The sources disagree on levels while agreeing on the ratios between towns, which is why this page leans on comparisons rather than a single ranked list.
This guide is part of The Downsizer's Suburban Starter Pack.