State ranking · HUD FMR
Illinois: Most Expensive Counties
The highest-cost counties in Illinois by 1-bedroom Fair Market Rent, FY 2026.
- $1,581
- Priciest 1BR — Cook County
- $854
- IL avg 1BR
- 50
- Counties ranked
The most expensive county for rent in Illinois is Cook County with a 1-bedroom FMR of $1,581/mo, which is 85% above the state average of $854. The national average 1-bedroom FMR is $959.
What "most expensive" really means for Illinois renters
These rankings come straight from HUD's FY 2026 Fair Market Rent schedule, which reports the 40th percentile of gross rents (utilities included, except telephone) for every county in Illinois. The top entry is Cook County with a 1-bedroom at $1,581, a studio at $1,480, 2-bedroom at $1,781, 3-bedroom at $2,294, and 4-bedroom at $2,653. Because HUD sets FMR per county (or per metro FMR area), these figures are the ceilings local housing authorities use to calibrate Section 8 Housing Choice Voucher payment standards — typically between 90% and 110% of FMR — which means they also approximate the moderate end of each county's documented rental market.
Compared with the Illinois state average of $854 for a 1-bedroom, the most expensive county is 85% above the state benchmark, and 65% above the US average of $959. High-rent counties almost always cluster in dense metropolitan FMR areas where housing supply is constrained, transit access is strong, and local wages support premium rents — which is also why voucher recipients frequently find fewer units at payment-standard rates in these counties without the help of HUD's Small Area FMR program. The ranking across all 50 counties shows the intra-state spread: moving between a top-ranked county and a mid-ranked one can mean hundreds of dollars per month in baseline rent before any amenity premium.
For budgeting, the 30% affordability rule says a household needs roughly $63,240/year to afford the most expensive 1-bedroom FMR in Illinois without being cost-burdened — well above the $34,160/year needed to afford the state average. That gap translates directly into rent-burden rates: counties at the top of this list tend to have the highest share of households paying more than 30% of income for rent, and the highest share of severely burdened renters (above 50% of income). Pair this ranking with the year-over-year FMR growth and rent burden pages to see whether today's most expensive counties are still tightening, or whether lower-ranked counties are catching up fastest.
Top 50 Most Expensive Counties in Illinois
| # | County | 1-BR | 2-BR | 3-BR | vs State Avg |
|---|---|---|---|---|---|
| 1 | Cook County | $1,581 | $1,781 | $2,294 | +85% |
| 2 | DuPage County | $1,581 | $1,781 | $2,294 | +85% |
| 3 | Kane County | $1,581 | $1,781 | $2,294 | +85% |
| 4 | Lake County | $1,581 | $1,781 | $2,294 | +85% |
| 5 | McHenry County | $1,581 | $1,781 | $2,294 | +85% |
| 6 | Will County | $1,581 | $1,781 | $2,294 | +85% |
| 7 | Kendall County | $1,562 | $2,050 | $2,819 | +83% |
| 8 | Grundy County | $1,118 | $1,459 | $1,979 | +31% |
| 9 | DeKalb County | $1,046 | $1,373 | $1,825 | +22% |
| 10 | Kankakee County | $1,011 | $1,326 | $1,745 | +18% |
| 11 | McLean County | $999 | $1,302 | $1,717 | +17% |
| 12 | Calhoun County | $995 | $1,218 | $1,568 | +17% |
| 13 | Clinton County | $995 | $1,218 | $1,568 | +17% |
| 14 | Jersey County | $995 | $1,218 | $1,568 | +17% |
| 15 | Madison County | $995 | $1,218 | $1,568 | +17% |
| 16 | Monroe County | $995 | $1,218 | $1,568 | +17% |
| 17 | St. Clair County | $995 | $1,218 | $1,568 | +17% |
| 18 | Menard County | $970 | $1,203 | $1,611 | +14% |
| 19 | Sangamon County | $970 | $1,203 | $1,611 | +14% |
| 20 | Champaign County | $946 | $1,122 | $1,436 | +11% |
| 21 | Piatt County | $946 | $1,122 | $1,436 | +11% |
| 22 | Henry County | $928 | $1,143 | $1,498 | +9% |
| 23 | Mercer County | $928 | $1,143 | $1,498 | +9% |
| 24 | Rock Island County | $928 | $1,143 | $1,498 | +9% |
| 25 | Boone County | $895 | $1,175 | $1,555 | +5% |
| 26 | Winnebago County | $895 | $1,175 | $1,555 | +5% |
| 27 | Ogle County | $852 | $1,118 | $1,365 | -0% |
| 28 | Putnam County | $851 | $937 | $1,212 | -0% |
| 29 | Macon County | $845 | $1,063 | $1,378 | -1% |
| 30 | Bond County | $836 | $916 | $1,154 | -2% |
| 31 | Cass County | $836 | $916 | $1,263 | -2% |
| 32 | Douglas County | $836 | $916 | $1,240 | -2% |
| 33 | Pulaski County | $836 | $916 | $1,274 | -2% |
| 34 | Schuyler County | $836 | $916 | $1,098 | -2% |
| 35 | Washington County | $836 | $916 | $1,242 | -2% |
| 36 | Pope County | $828 | $1,087 | $1,375 | -3% |
| 37 | La Salle County | $822 | $1,079 | $1,441 | -4% |
| 38 | Marshall County | $818 | $1,039 | $1,346 | -4% |
| 39 | Peoria County | $818 | $1,039 | $1,346 | -4% |
| 40 | Stark County | $818 | $1,039 | $1,346 | -4% |
| 41 | Tazewell County | $818 | $1,039 | $1,346 | -4% |
| 42 | Woodford County | $818 | $1,039 | $1,346 | -4% |
| 43 | Adams County | $811 | $1,064 | $1,327 | -5% |
| 44 | Brown County | $810 | $1,063 | $1,275 | -5% |
| 45 | Lee County | $810 | $916 | $1,274 | -5% |
| 46 | Alexander County | $807 | $992 | $1,380 | -6% |
| 47 | Jo Daviess County | $796 | $954 | $1,271 | -7% |
| 48 | Hancock County | $791 | $916 | $1,111 | -7% |
| 49 | De Witt County | $790 | $1,036 | $1,242 | -7% |
| 50 | Williamson County | $790 | $1,037 | $1,369 | -7% |
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Methodology
Rankings are based on FY 2026 Fair Market Rents (FMR) published by the U.S. Department of Housing and Urban Development (HUD). FMR represents the 40th percentile of gross rents for standard quality units in a given area. Counties are ranked by 1-bedroom FMR in descending order. "vs State Avg" compares each county's 1-bedroom FMR to the Illinois average.
Read our methodology — how this data is sourced, computed, and verified.