County Property Tax Calculator 2025

What Is a County Property Tax?

A county property tax is the portion of your total property tax that funds county government services — courts, jails, roads, public health, libraries, and often a large share of the local school budget. In most of the U.S., the county is the level of government that actually bills and collects the tax, even when the money is shared with cities and school districts. The rate you see in the calculator above is the county's combined levy expressed as a percentage of assessed value.

County rates are the single biggest reason your bill differs from a neighbor's in another county of the same state. A homeowner in Cook County, Illinois can pay more than twice the effective rate of a homeowner in a downstate Illinois county, even though both are "Illinois." That is why looking up your specific county matters more than knowing your state average.

Understanding Millage Rates

Counties express their tax rate in millage — the number of dollars charged per $1,000 of assessed value. A rate of 20 mills means $20 of tax for every $1,000 of assessed value, or 2.0%. To convert mills to a percent, divide by 10; to convert a percent to mills, multiply by 10. When you see "1.66%" in the calculator, that is 16.6 mills.

The total millage on your bill is the sum of several separate millages: the county general fund, the county road fund, the school district, the city or town, and any special districts. Each is voted on or set by its own board, so the combined rate creeps up when any one of them raises its levy. Our calculator rolls these into a single effective percentage so you do not have to add the mills yourself.

How Counties Assess Property

Before a rate can be applied, the county assessor places a value on your property. Most counties assess at market value, but several use a statutory ratio: Michigan assesses at 50% of market value, Ohio at 35%, Missouri at 19%, and Tennessee at just 25%. The taxable value is that assessed value minus any exemptions (such as a homestead exemption).

Revaluation does not happen every year everywhere. Some counties reappraise annually, others on a 2-, 3-, 4-, or 6-year cycle, with smaller "trending" adjustments in between. The year your county revalues is often the year your bill jumps, because the assessed value catches up to a hot market. Knowing your county's cycle — shown in each state guide — helps you predict and prepare for changes.

County vs State vs City Tax

It is easy to confuse the layers. The state sets the legal framework (assessment ratios, exemption rules, appeal rights) but usually collects little property tax directly. The county bills and collects, and funds county services plus a share of schools. The city or town adds its own levy for police, fire, and parks. The school district usually adds the largest levy of all. Your single county tax bill is really a bundle of all four, which is why the calculator's breakdown shows assessed value, exemption, taxable value, rate, and the resulting tax step by step.

How to Look Up Your County Rate

Use the tool at the top of this page: pick your county from the URL (for example, /county?name=harris for Harris County, Texas) and the calculator auto-fills the local rate and average home value. Enter your own assessed value and any homestead exemption, choose whether the property is your primary residence or an investment, and press Calculate. The result compares your tax to the county average, the state average, and the U.S. average so you can see exactly where you stand.

If your county is not yet in the database, start from the county map to find a neighboring county with a similar rate, or use your state's guide for the statewide average as a starting point.

How to Lower Your County Tax

You have the same four levers as anywhere else, applied at the county level: (1) appeal the assessed value if it exceeds recent comparable sales — file with the county board of equalization or assessment appeals within the deadline printed in your state guide; (2) claim exemptions such as the homestead exemption, which many counties auto-apply only after you file; (3) watch reassessment triggers like a remodel or sale; and (4) model the result with our calculator before acting so you know the dollar payoff.

Investment and rental properties usually receive no homestead exemption and, in many counties, carry a surcharge (the calculator adds 10% for investment-type property). If you live in the home, filing the primary-residence exemption is the fastest way to cut the bill.

County Tax Across the U.S.

The range is dramatic. High-cost suburban counties such as Westchester and Nassau in New York, and Essex and Bergen in New Jersey, routinely exceed 2.0% effective. At the other end, counties in Hawaii, Alabama, and Louisiana often sit below 0.6%. Even within a single state the spread is wide: Texas border counties can be near 1.3% while some Austin-area counties approach 2.0%. The calculator's comparison bars make these gaps visible at a glance.

Frequently Asked Questions — County Tax

What does "county tax rate" mean?

It is the county's combined levy — county government plus its share of schools and special districts — expressed as a percent of assessed value. It does not include city tax, which is billed separately but often on the same bill.

How do I convert mills to a percent?

Divide the millage by 10. Twenty mills equals 2.0%; 16.6 mills equals 1.66%. The calculator shows the percent directly.

Why is my county rate different from my state average?

Each county sets its own levy and serves different school districts, so rates vary block by block across a state. The state average blends high- and low-rate counties together.

Is my assessed value the same as my home's price?

Not always. Some states assess at a fraction of market value (Michigan 50%, Ohio 35%, Tennessee 25%), and many cap annual growth, so a long-time owner's assessed value can lag far behind the sale price.

How do I appeal my county assessment?

File with your county board of equalization or assessment appeals, usually within 30 to 45 days of the notice, with recent comparable sales. Each state's deadline is listed in its guide.

Do investment properties pay more?

Often yes. They usually get no homestead exemption and may carry a surcharge; the calculator models a 10% investment surcharge so you can see the difference.

Are county property taxes deductible?

Yes, on Schedule A, but the $10,000 SALT cap limits the total state and local deduction for higher-income filers.

Where can I find my own county's rate?

Use this lookup tool with your county's name in the URL, or start from the county map and drill into your state.

A Worked County Example

Suppose a homeowner in Harris County, Texas buys a $280,000 primary residence. The county rate is about 1.66%. With Texas's $100,000 homestead exemption, the taxable value becomes $180,000. The base tax is $180,000 × 1.66% = $2,988 per year, or about $249 a month. Without the homestead exemption, the same home would owe $4,648 a year — a $1,660 difference that repeats every year. The calculator shows exactly this kind of gap, which is why filing the homestead exemption is the single highest-value action for a new Texas homeowner.

Now make it an investment property: removing the homestead exemption and adding the typical 10% surcharge raises the bill to roughly $5,100 a year. A landlord must therefore charge enough rent to cover that tax plus insurance, maintenance, and debt service — another reason the property type selector matters in the tool.

Your County Tax Calendar

Property tax follows a predictable yearly rhythm, and missing a step can cost you for years:

• Late winter–spring: The assessor mails a notice of assessed value. Read it. If the value looks high, this is your window to act.
• 30–45 days after the notice: The appeal deadline. File with the county board of equalization or assessment appeals with comparable sales. Miss it and you wait a full year.
• Summer: Counties and school districts hold budget hearings where the next year's millage is set. Public comment can influence the rate.
• Fall: Tax bills are mailed. If you escrow, your lender pays them and may adjust your monthly payment.
• Year-round: File or renew exemptions (homestead, senior, veteran) with the county — most do not renew automatically.

Mark these dates and you will never be surprised by a jump in your bill. The state guides on this site list the exact appeal window for your state.

What If You Disagree With the Assessor?

Disagreement is normal and appealable. Gather three to five recent sales of similar homes in your neighborhood, note any condition issues (foundation, roof, flooding) that the assessor may not have seen, and present them to the county board. A successful appeal lowers the taxable base, which then flows through to every future bill — not just the current year. Many counties report appeal success rates above 40% when homeowners bring comparable sales, so the effort is usually worth it.