Total monthly cost of ownership
Cost to Own a Home in Oak Brook, Illinois
A $868,000 home here costs
$6,641per month, all in — with 20% down at today's 6.66% 30-year fixed rate.
A standard mortgage calculator would have told you $4,462. The real number is $2,179 higher every month — 49% more than the payment most buyers budget for.
Where every dollar goes
Only the first line is a mortgage payment. Change any assumption above and every figure below recalculates.
Oak Brook against Cook County and Illinois
| Measure | Oak Brook | Cook County |
|---|---|---|
| Median home value | $867,900 | $305,200 |
| Median property tax | $10,001 | $6,053 |
| Effective tax rate | 1.152% | 1.983% |
| Median gross rent | $2,921 | $1,381 |
| Population | 8,028 | 5,185,812 |
Oak Brook extends across 2 counties. Figures here use Cook County, where most of its housing sits.
The weather behind that power bill
Oak Brook sits in Cook County, which averages a high of 84.0°F in its hottest month and a low of 16.1°F in its coldest, with 33.23" of precipitation a year and 35% of it in a single three-month stretch. That climate drives 822 cooling and 6,364 heating degree days, which is what sets the $214 electricity line above.
See the full climate breakdown for Cook County — month by month temperatures, rainy season timing, snowfall and heating and cooling costs.
Other cities in Cook County
Common questions
How much does it cost to own a home in Oak Brook?
A $868,000 home in Oak Brook, Illinois costs approximately $6,641 per month with 20% down at 6.66%. That is $4,462 principal and interest, $833 property tax, $340 homeowners insurance, $282 utilities and $723 set aside for maintenance.
What is the property tax rate in Oak Brook?
Oak Brook has an effective property tax rate of 1.152%, based on a median home value of $867,900 and median real estate taxes of $10,001. That is lower than the Cook County average of 1.983%.
What is the average home price in Oak Brook?
The median owner-occupied home value in Oak Brook, Illinois is $867,900, against $305,200 across Cook County.
Is it cheaper to rent or buy in Oak Brook?
Median gross rent in Oak Brook is $2,921 a month, against $6,641 to own the median home all in. Renting costs less month to month here, though renting builds no equity.
Sources & methodology
- Median home value, real estate taxes, gross rent and population for Oak Brook — US Census Bureau, American Community Survey ACS 2023 5-Year, place-level tables.
- Homeowners insurance — NAIC average premium for Illinois.
- Electricity price — EIA Electric Power Monthly Table 5.6.A.
- Mortgage rate — Freddie Mac PMMS, refreshed weekly.
- Maintenance (1%/yr) and water and sewer ($68/mo) are national estimates. Every assumption above is editable.