The basic formula: assessed value times tax rate

Property tax is calculated by multiplying your home's assessed value by your local tax rate. The assessed value is not what you paid for the house or what it would sell for today — it is a value set by your county or municipality, usually lower than market value. The tax rate is a percentage set by your local government and varies by location.

Here is the real calculation: if your home is assessed at $300,000 and your tax rate is 1.2%, your annual property tax is $3,600. The math is straightforward, but the two numbers that go into it — assessed value and tax rate — come from different places and change on different schedules.

Most property owners receive a tax bill once or twice a year from their county assessor or tax collector. If you want to calculate what you owe before that bill arrives, or if you are comparing two homes, you need to know where to find both numbers and how they are determined.

Key Takeaways

  • Property tax equals the assessed value of your home multiplied by your local tax rate, both of which are public information you can find through your county assessor's office.
  • Assessed value is set by your county and is usually 20% to 40% of what your home would sell for, though the percentage varies by state.
  • Tax rates are set by your city, county, and school district combined, and they change year to year based on local budget needs.
  • You can find your assessed value and tax rate on your property tax bill, your county assessor's website, or by calling the assessor's office directly.
  • If you believe your assessed value is too high, most states allow you to file a formal challenge called an assessment appeal or reassessment request.

Finding your assessed value

Your assessed value is the dollar amount your county assessor assigns to your property for tax purposes. It is not the same as your home's market value, appraisal value, or what you owe on your mortgage. The assessor estimates it based on sales of similar homes in your area, the condition of your property, and local market trends.

You can find your assessed value on your property tax bill — it is usually listed near the top or middle of the page. If you do not have a recent bill, visit your county assessor's website. Most counties have an online property search tool where you enter your address and see the assessed value, lot size, year built, and other details. Some assessor websites require a parcel number instead of an address; you can find this on your tax bill or deed.

If the website is not working or you cannot find your property, call your county assessor's office directly. They can tell you the assessed value over the phone and explain how it was calculated. This is a public record, so there is no privacy barrier to getting this information.

Understanding tax rates and where they come from

Your tax rate is expressed as a percentage and is set by your local government. It is not a single number — it is actually the sum of rates from multiple taxing bodies. Your property tax bill typically includes a rate from your county, your city or township, your school district, and sometimes a special district (like a fire district or library district).

For example, your county might set a rate of 0.5%, your city 0.4%, and your school district 0.3%, for a combined rate of 1.2%. Each body sets its own rate based on its budget needs. If your school district needs more money, it can raise its portion of the rate. If your county cuts its budget, it can lower its portion.

Tax rates change every year. You can find your current rate on your property tax bill, listed as a percentage or sometimes as a dollar amount per $1,000 of assessed value. Your county assessor's website usually shows the rate breakdown by taxing body as well. If you are buying a home and want to know the tax rate before closing, ask your real estate agent or contact the assessor's office in that county.

Step-by-step calculation with a real example

Let's walk through a complete calculation. Say you own a home in a county where the assessed value is $250,000 and the combined tax rate is 1.15%.

Step 1: Write down the assessed value: $250,000

Step 2: Write down the tax rate as a decimal. Convert 1.15% to 0.0115.

Step 3: Multiply: $250,000 × 0.0115 = $2,875

Your annual property tax is $2,875. If your county bills twice a year, each bill would be around $1,437.50. If it bills once a year, you pay $2,875 in a single payment.

Some counties express the tax rate differently — as dollars per $1,000 of assessed value instead of a percentage. If your rate is listed as $11.50 per $1,000, the math is: ($250,000 ÷ $1,000) × $11.50 = $2,875. The answer is the same; the format is just different.

How assessed value changes over time

Your assessed value is not fixed forever. Most counties reassess properties every year, and some do it every three to five years. When the assessor reassesses, they look at recent sales of similar homes, changes to your property (like an addition or renovation), and overall market trends in your area.

If your home's market value goes up, your assessed value usually goes up too, which means your tax bill increases. If the market softens and home values fall, your assessed value may decrease. Some states have assessment caps that limit how much the assessed value can increase in a single year, even if the market is booming. These caps vary by state — some allow increases of 2% per year, others 5%, and some have no cap at all.

You will receive a notice when your assessed value changes. Read it carefully. If you think the new value is too high, most states allow you to file a formal challenge. The process and important date vary by county, but you typically have 30 to 60 days from the notice date to file. Contact your county assessor's office to learn the important date and process in your area.

What affects your tax bill besides assessed value and rate

The basic formula is assessed value times tax rate, but your actual bill may include other amounts. Some homeowners pay less tax because they may have access to for an exemption — for example, senior citizens, disabled veterans, or agricultural property owners often receive exemptions that reduce their assessed value or tax rate.

Your bill may also include charges for services like water, sewer, or trash collection, though these are technically separate from property tax. Some counties add fees for school bonds or special district improvements. Read your tax bill carefully to see what you are paying for. If you see a charge you do not understand, call the tax collector's office and ask what it covers.

If you pay property tax through an escrow account (your mortgage lender collects it and pays the county), your lender estimates the annual tax and divides it into your monthly payment. The estimate may be higher or lower than what you actually owe. At the end of the year, your lender reconciles the difference and adjusts your next year's escrow payment.

Comparing taxes on two different properties

If you are thinking about buying a home and want to compare property taxes, you need the assessed value and tax rate for each property. Do not assume the tax will be lower just because the purchase price is lower — assessed values and tax rates vary by location, and a cheaper house in a high-tax area can have a higher tax bill than an expensive house in a low-tax area.

Here is how to compare: find the assessed value and tax rate for each property, multiply them together, and compare the results. If you are buying in a new county, remember that the assessed value may be different from the purchase price. A home you are buying for $400,000 might be assessed at $300,000 in one county and $350,000 in another, depending on local assessment practices.

Your real estate agent can usually provide the assessed value and tax rate for any property you are considering. If they cannot, contact the assessor's office in that county directly. This information is public and takes only a few minutes to find.

Frequently Asked Questions

Is assessed value the same as appraised value?

No. Appraised value is what a professional appraiser estimates your home is worth, usually for a mortgage or insurance purpose. Assessed value is what your county sets for tax purposes and is typically lower. An appraisal is done once for a specific reason; assessed value is set by the county and updated periodically.

Can I lower my property tax by lowering my assessed value?

You cannot lower it yourself, but you can challenge it if you believe it is too high. File an assessment appeal or reassessment request with your county assessor within the important date shown on your assessment notice. You will need to show evidence that the value is incorrect — for example, a recent appraisal, comparable sales data, or documentation of property damage.

Why did my property tax bill go up even though the tax rate stayed the same?

Your assessed value likely increased. Even if the tax rate does not change, your bill goes up if your home's assessed value rises. This happens when the assessor reassesses your property and finds it is worth more than the previous year's estimate.

How do I know if my tax rate is high or low compared to other places?

Tax rates vary widely by state and county. Your county assessor's office can tell you your current rate and how it compares to neighboring counties. You can also search online for "property tax rates by county" in your state to see a ranking. Keep in mind that a lower rate does not always mean lower taxes — it depends on assessed values too.

What happens if I do not pay my property tax?

Your county can place a lien on your home, charge penalties and interest, and eventually foreclose and sell the property to recover the unpaid tax. If you cannot pay in full, contact your tax collector's office when ready to ask about payment plans or hardship options.