Why property tax is a county and local matter
Property tax in the United States is set and collected locally, so the rate you pay is a county story, not a national one.
Each county assessor values your home, and county, city, school and special districts each add a levy on top.
That is why average effective rates vary so widely: Cook County, Illinois runs near 1.98 percent of market value, while Maricopa County, Arizona sits around 0.47 percent.
On a $400,000 home that is roughly $7,920 a year in Cook County versus about $1,880 in Maricopa.
The effective rate — actual tax paid divided by market value — is the fairest way to compare counties, because it folds together assessment practices and every local levy into one number.
Our per-county property tax calculator multiplies your home value by the county's average effective rate to show annual and monthly figures, so you can compare counties on the same basis before you buy or budget.
How combined sales tax stacks state, county, and city
A sales tax rate is really a stack. The state sets a base rate, then the county adds its own local tax, and the city or transit district can layer more on top.
The number you pay at checkout is the combined rate. In Los Angeles County the combined rate reaches about 9.75 percent, and in Cook County it climbs to roughly 10.25 percent, while Miami-Dade County stays near 7 percent.
Two counties in the same state can differ sharply for the same reason: Texas caps local add-ons, so Harris County lands around 8.25 percent, but California counties range from 7.75 percent to over 10 percent depending on district taxes.
Even within one county, individual cities can push the rate slightly higher.
Our per-county sales tax calculator applies a typical combined rate for each county, adding the tax to any purchase amount and showing the total, so you can estimate the true cost of a purchase wherever you are shopping.
Using the per-county calculators and confirming your bill
To use these tools, pick your county, then choose the property tax or sales tax calculator.
For property tax, enter your home value and the tool applies the county's average effective rate to estimate annual and monthly tax; lenders often collect that amount monthly into escrow.
For sales tax, enter a purchase amount and the tool adds the combined state, county and city rate to show the total. Every figure here is an estimate built on average effective county rates.
Your actual property tax bill depends on your assessed value, any homestead, senior or veteran exemptions, and the specific school and special districts your parcel falls in — factors that can move the number well above or below the average.
Sales tax can also shift by exact address and by category, since many counties reduce or exempt groceries and prescriptions. Always confirm your precise rate, assessment and exemptions with the county assessor or property appraiser before relying on a figure.