The tax rate on a Cook County bill is a percentage of equalized assessed value, and for tax year 2025 (the bills due October 1, 2026) it ranges from about 6.4% in New Trier Township to 19.0% in Thornton Township. Chicago's rate is 6.85% in most of the city. The table below is the median composite rate across the tax codes in each township, from the county's 2025 rate file; the range shows how much it varies inside a township, because school, park, library and municipal levies differ block by block.
2025 composite tax rates by township
| Township | Region | Median rate | Range across tax codes |
|---|---|---|---|
| Thornton | south & west | 19.02% | 12.92% – 35.78% |
| Calumet | south & west | 18.44% | 13.98% – 29.01% |
| Rich | south & west | 15.47% | 7.52% – 29.75% |
| Bloom | south & west | 13.42% | 9.20% – 31.71% |
| Bremen | south & west | 12.66% | 8.29% – 22.40% |
| Proviso | south & west | 12.18% | 5.85% – 17.88% |
| Oak Park | south & west | 11.94% | 11.66% – 12.22% |
| Berwyn | south & west | 11.68% | 10.95% – 12.41% |
| Cicero | south & west | 11.49% | 11.49% |
| Worth | south & west | 11.28% | 7.60% – 14.43% |
| Stickney | south & west | 11.16% | 8.77% – 12.58% |
| Riverside | south & west | 10.62% | 8.33% – 12.32% |
| Lyons | south & west | 10.19% | 6.57% – 14.16% |
| Palos | south & west | 9.92% | 8.00% – 11.66% |
| Leyden | north | 9.85% | 7.26% – 20.19% |
| River Forest | south & west | 9.83% | 9.83% |
| Orland | south & west | 9.12% | 7.78% – 10.84% |
| Wheeling | north | 8.78% | 7.17% – 10.85% |
| Palatine | north | 8.73% | 6.30% – 9.63% |
| Hanover | north | 8.72% | 7.31% – 9.73% |
| Schaumburg | north | 8.64% | 8.15% – 9.57% |
| Elk Grove | north | 8.13% | 6.70% – 9.03% |
| Niles | north | 8.00% | 6.28% – 10.59% |
| Maine | north | 7.98% | 6.57% – 10.50% |
| Norwood Park | north | 7.97% | 6.83% – 8.51% |
| Evanston | north | 7.49% | 7.33% – 8.37% |
| Lemont | south & west | 7.46% | 6.46% – 7.63% |
| Rogers Park | city | 7.38% | 6.85% – 7.60% |
| Barrington | north | 7.11% | 6.18% – 8.94% |
| Lake View | city | 7.10% | 6.85% – 7.73% |
| Lake | city | 6.88% | 6.85% – 9.15% |
| Hyde Park | city | 6.88% | 6.85% – 9.87% |
| South Chicago | city | 6.88% | 6.85% – 7.27% |
| West | city | 6.88% | 6.85% – 8.88% |
| Jefferson | city | 6.88% | 6.85% – 8.06% |
| North Chicago | city | 6.87% | 6.85% – 7.22% |
| Northfield | north | 6.72% | 6.12% – 7.92% |
| New Trier | north | 6.36% | 5.08% – 7.19% |
State equalization factor for 2025: 3.0300. Source: Cook County Clerk 2025 tax rate file by tax code, weighted by residential parcels, as loaded September 6, 2026.
How the rate turns into a bill
Equalized assessed value is your assessed value times the state equalizer. Residential property is assessed at 10% of market value, so a $300,000 home is assessed at $30,000, equalized to $90,900. Multiply by the rate and subtract exemptions: at Chicago's 6.85% that is $6,227 before the Homeowner Exemption ($10,000 of equalized value, worth $685 here), so about $5,540. The same house in Worth Township at 11.28% is about $9,120; in Thornton at 19.02% about $15,390.
Why south suburban rates are so high
A rate is a levy divided by a tax base. South suburban school districts and municipalities levy against a base with fewer commercial parcels and lower home values, so the same levy needs a higher rate. Chicago and the north shore have deeper bases and lower rates even where the bills are higher in dollars. The rate is not something you can appeal; it is set by the taxing bodies' levies and computed by the County Clerk after appeals close.
What you can change
Only the assessed value is yours to challenge. A 9% reduction on a $30,000 assessment in Worth Township is about $920 a year at the median rate; the same reduction in Thornton is about $1,550. The higher the rate, the more each assessment dollar costs, which is why appeals in the south suburbs are worth more per dollar of assessed value than anywhere else in the county. See your own number with the free property check, and check whether your township's appeal window is open.
