The Basic Formula: Assessed Value Times Tax Rate

Your property tax bill is the result of one calculation: the assessed value of your property multiplied by the tax rate set by your local government. The assessed value is not what you paid for the house or what it could sell for today — it is a value assigned by your county assessor's office, usually lower than market value. The tax rate is expressed as a percentage or as dollars per $1,000 of assessed value, and it varies by county, city, and school district.

The reason there are multiple tax rates is that property taxes fund different services. Your bill typically includes a portion for county services, a portion for city or township services, and a portion for schools. Each of these bodies sets its own rate, and they are added together to create your total bill. A property in one county might pay 1.2% of assessed value in tax, while an identical property across the county line might pay 0.8% — the difference is purely which taxing bodies serve that location.

Key Takeaways

  • Your property tax bill equals the assessed value of your property times the tax rate, with the assessed value usually set by your county assessor's office.
  • Tax rates vary by location because different counties, cities, and school districts each set their own rate and add them together.
  • The assessed value is typically lower than the market value of your home and is updated on a schedule that varies by state — some states reassess every year, others every three to five years.
  • You can usually find your assessed value and tax rate on your property tax bill or by searching your county assessor's website using your address.
  • If you believe your assessed value is too high, most counties allow you to file a formal challenge called an assessment appeal or assessment protest.

How Assessed Value Is Determined

The assessed value starts with a property appraisal performed by the county assessor's office. Assessors use several methods to arrive at a value: they may look at recent sales of similar properties in your area, estimate the cost to rebuild your house from scratch, or calculate the income a rental property generates. Most assessors use a combination of these methods. The appraisal is not a full inspection — assessors typically work from public records, aerial photos, and occasional physical drive-bys rather than entering every home.

Once an initial value is set, it is updated on a schedule that depends on your state. Some states reassess all properties every year. Others reassess every three to five years, or only when a property changes hands. A few states use a hybrid system where some properties are reassessed annually and others on a longer cycle. You can find your state's reassessment schedule by searching "[your state] property tax reassessment schedule" or by calling your county assessor's office.

The assessed value is often lower than the market value because many states cap how much the assessed value can increase in a single year, even if the market value rises sharply. California, for example, caps annual increases at 2% unless the property is sold. This means a home that has not changed hands in ten years may have an assessed value well below what it would sell for today.

Tax Rates and How They Are Set

Tax rates are set by elected officials in each taxing body — the county commission, city council, and school board. Each body decides how much money it needs to operate and divides that by the total assessed value of all property in its jurisdiction to arrive at a rate. This is why tax rates can change year to year: if a school district's budget increases but property values stay flat, the rate goes up. If property values rise but the budget stays the same, the rate may go down.

Tax rates are usually expressed in one of two ways. Some jurisdictions state the rate as a percentage — for example, 1.25% of assessed value. Others express it as a dollar amount per $1,000 of assessed value — for example, $12.50 per $1,000. Both methods produce the same result; the second format is simply a way of breaking down the percentage into smaller, easier-to-read numbers. Your property tax bill or your county assessor's website will show which format your jurisdiction uses.

Reading Your Property Tax Bill

Your property tax bill itemizes the assessed value, the tax rate, and the amount owed to each taxing body. A typical bill shows the assessed value at the top, then lists each taxing body (county, city, school district) with its own rate and the dollar amount you owe to it. The total of all these amounts is your annual property tax bill. Some jurisdictions allow you to pay in two installments per year; others require a single annual payment. The due date and payment method are shown on the bill itself.

If you cannot find your bill or want to verify the numbers, most county assessor's offices maintain searchable online databases. You can usually search by address or parcel number to see the assessed value, the tax rate breakdown, and sometimes a history of past assessments. If you own property in multiple counties, you will receive separate bills from each one.

What Happens If You Disagree With Your Assessed Value

If you believe your assessed value is too high, you have the right to file a formal challenge. This process is called an assessment appeal, assessment protest, or property tax appeal, depending on your state. The first step is usually to contact your county assessor's office and ask for the deadline and procedure in your jurisdiction — deadlines typically fall within 30 to 60 days of when the assessment is mailed to you, though some states allow year-round appeals.

To file an appeal, you will usually need to submit a written request that explains why you believe the value is wrong. Common reasons include recent damage to the property, an error in the property description (wrong square footage, for example), or evidence that similar properties in your area have lower assessed values. You may need to provide supporting documents such as a recent appraisal, photos of damage, or a list of comparable sales. Some counties require you to pay a small filing fee, though many waive it if your appeal is successful.

If the assessor's office denies your appeal or you disagree with their response, you can usually appeal to a county board or tribunal. This second-level appeal may require you to appear in person or submit additional evidence. The process and timeline vary significantly by state, so contact your assessor's office or search "[your county] property tax appeal" to find the specific rules that apply to you.

Exemptions and Special Assessments

Some properties receive a tax exemption that reduces or eliminates the property tax bill. Common exemptions include those for owner-occupied homes (in some states), agricultural land, religious organizations, and government buildings. If you think you may be may have access to to an exemption, contact your county assessor's office to ask what is available in your jurisdiction and what documents you need to provide to claim it.

In addition to the standard property tax, some properties are subject to special assessments — additional charges for specific improvements like new roads, drainage systems, or streetlights that benefit a particular area. Special assessments are calculated differently than regular property tax and are often paid over several years. They appear as a separate line item on your bill or as a separate notice.

Frequently Asked Questions

Why is my assessed value different from what I paid for my house?

Assessed value and purchase price are two different things. The assessed value is set by the county assessor based on comparable sales and property characteristics, while the purchase price is what you negotiated with the seller. If you bought during a market peak or valley, your purchase price may be higher or lower than the assessed value. Over time, assessed values and market values tend to move in the same direction, but they are rarely identical.

Can my property tax bill go down?

Yes, in two ways. If your assessed value decreases — because of damage, a successful appeal, or a reassessment in a declining market — your bill will go down. If the tax rates set by your local government decrease, your bill will also go down. However, in most places, property tax bills trend upward over time because assessed values and tax rates both tend to increase.

What is the difference between assessed value and market value?

Market value is what your home would sell for today. Assessed value is what the county assessor says it is worth for tax purposes, and it is usually lower. Some states cap how much assessed value can increase annually, which causes assessed value to lag behind market value in rising markets. In declining markets, assessed value may lag behind market value in the other direction.

How often does my assessed value change?

The frequency depends on your state. Some states reassess all properties annually. Others reassess every three to five years, or only when a property is sold. A few states use a split system where some properties are reassessed yearly and others on a longer schedule. Check your county assessor's website or call their office to find out the reassessment schedule for your property.

Do I have to pay property tax if I own my home outright?

Yes. Property tax is owed by anyone who owns real estate, whether the property is paid off or financed. If you have a mortgage, your lender may collect property tax as part of your monthly escrow payment and pay it on your behalf, but you are still responsible for it. If you own the property outright, you receive the bill directly and must pay it yourself.