Property taxes start with your home's assessed value, multiplied by your local tax rate
Property tax is calculated by taking the assessed value of your property—what your local assessor says it is worth—and multiplying it by the tax rate set by your city, county, or school district. The result is the dollar amount you owe each year. The assessed value is not the same as what you paid for the house or what it would sell for today. It is a separate number determined by your local assessor's office, and the tax rate is a percentage set by local government bodies that need funding.
The process happens in two separate steps, controlled by two different entities. Your assessor's office determines the value. Your local government—usually the county or a combination of the county, city, and school district—sets the rate. Both numbers change, but on different schedules and for different reasons.
Key Takeaways
- Your assessed value is set by your county or local assessor's office, usually every one to three years, and is based on recent sales of similar homes in your area, not on what you paid.
- The tax rate is set by your city, county, school district, or a combination of these, and is expressed as a percentage of assessed value or as a dollar amount per $1,000 of value.
- You can challenge your assessed value through a formal appeal process if you believe it is too high, and the important date to file is usually 30 to 60 days after you receive your assessment notice.
- Property tax rates and assessment schedules vary significantly by state and county, so what happens in one place may not happen in another.
- Your final tax bill includes taxes owed to multiple entities—county, city, school district, and sometimes special districts—each with its own rate.
How assessors determine your home's value
Your local assessor's office estimates your property's value by comparing it to similar homes that sold recently in your neighborhood. They look at the sale price of homes with comparable size, age, condition, and location. If your house is 2,000 square feet, built in 1995, and in good condition, they find other 2,000-square-foot homes from the same era in the same area that sold in the past year or two, and use those prices as a guide. They may also adjust for differences—if your home has a pool and the comparable home does not, they add value; if yours needs a new roof, they subtract.
Some assessors use computer models that factor in these details automatically. Others send assessors to walk the property, photograph it, and record its features. The frequency of reassessment varies by state. Some states reassess every year. Others do it every three years or only when a property changes hands. A few states, like California, assess at the time of sale and then increase the value by a small percentage each year until the next sale.
The assessed value is usually lower than the market value—the price a buyer would actually pay. States set this relationship differently. Some cap assessed value at 50 percent of market value. Others use 100 percent. Your assessor's office should publish the ratio they use, and you can find your property's assessed value on your tax bill or by calling the assessor's office directly.
Who sets the tax rate and how it works
The tax rate is set by the local government bodies that need the money. In most places, this means your county, your city (if you live in one), your school district, and possibly special districts for fire, water, or libraries. Each one sets its own rate, and your total tax bill is the sum of all of them. If your county rate is 0.8 percent, your city rate is 0.3 percent, and your school district rate is 1.2 percent, your combined rate is 2.3 percent of your assessed value.
Tax rates are usually expressed in one of two ways. Some places show them as a percentage—2.3 percent of assessed value. Others show them as a dollar amount per $1,000 of assessed value—$23 per $1,000, which is the same thing. A few states use a mill rate, where one mill equals $1 per $1,000 of value, so 23 mills is the same as $23 per $1,000.
The rate is set during a budget process. The county or city calculates how much money it needs to run schools, fix roads, pay police, and maintain other services. It divides that total by the total assessed value of all property in its jurisdiction, and that division produces the tax rate. If the jurisdiction needs more money next year, the rate goes up. If it needs less, the rate goes down. The rate can also change if the total assessed value in the area changes—if many homes are reassessed higher, the rate might go down because the same revenue comes from a larger tax base.
When assessments change and how often you pay
Your assessed value can change for several reasons. The most common is a routine reassessment on the schedule your state uses. If your state reassesses every three years, your value will be updated every three years whether you want it to or not. A reassessment also happens when you sell the property or make major improvements—adding a room, finishing a basement, or replacing the roof. Some states reassess after a sale; others do not.
You will receive a notice when your assessment changes. The notice tells you the new assessed value, the important date to challenge it (usually 30 to 60 days), and how to file an appeal if you disagree. If you do not challenge it by the important date, the new value stands until the next reassessment.
Property taxes are usually paid once or twice a year, depending on where you live. Some counties bill in one lump sum. Others split it into two payments, typically in spring and fall. If you have a mortgage, your lender may require you to pay property taxes through an escrow account, where you pay a portion each month along with your mortgage payment, and the lender pays the bill when it is due.
How to challenge your assessed value
If you believe your assessed value is too high, you can file a formal appeal. The process and important date vary by state and county, but the basic steps are the same. First, you will receive an assessment notice in the mail. Read it carefully and note the important date to file an appeal—this is usually 30 to 60 days after the notice is mailed. Do not miss this important date; in most places, you cannot appeal after it passes.
To build your case, gather evidence that your home is worth less than the assessed value. This might include a recent appraisal from a lender, a real estate agent's opinion of value, or sales prices of similar homes that sold for less. You can also document problems with the assessment itself—if the assessor recorded your home as having four bedrooms when it has three, or listed the square footage incorrectly, that is grounds for appeal.
File your appeal with the assessor's office or the board of review (the name varies by location). Include your evidence and a written explanation of why you think the value is wrong. Some jurisdictions allow you to present your case in person at a hearing; others review appeals on paper only. If you disagree with the result, you may be able to appeal to a higher body, such as a county board or a state tax court, but this usually requires hiring a tax attorney and is expensive.
How property taxes differ by state and location
Property tax systems vary dramatically across the United States. Some states have high property tax rates and assess homes frequently. Others have low rates and reassess rarely. New Jersey, Illinois, and Connecticut have some of the highest effective property tax rates in the country, while Hawaii, Alabama, and Louisiana have some of the lowest. Within a single state, rates can also vary widely between counties and school districts.
Some states offer homestead exemptions, which reduce the assessed value of a primary residence by a fixed amount or percentage. For example, a state might exempt the first $50,000 of value from taxation, so a home assessed at $300,000 is taxed as if it were worth $250,000. Other states offer exemptions for seniors, veterans, or people with disabilities. These exemptions are set by state law and vary in size and who qualifies.
A few states, like California, limit how much the assessed value can increase each year, even if the market value rises. California caps increases at 2 percent per year until the property is sold. This keeps taxes stable for long-term owners but can create large disparities between neighbors—two identical homes on the same street might have very different tax bills if one was bought decades ago and the other recently.
Reading your property tax bill and understanding the charges
Your property tax bill lists the assessed value, the tax rate or rates, and the total amount due. It also breaks down which entities are receiving the money. You might see a line for county tax, a line for city tax, a line for school district tax, and lines for any special districts. Each line shows its own rate and the dollar amount you owe to that entity. Add them together and you get your total bill.
The bill also shows the due date and where to send payment. If you pay late, you will owe a penalty and interest. The amount and timing of penalties vary by location, but they can add up quickly, so pay on time if you can. If you cannot pay the full amount, contact your assessor's office or tax collector to ask about payment plans or hardship programs; some jurisdictions offer these.
If you do not understand a line item on your bill, call your local tax collector's office. They can explain what each charge is for and answer questions about your rate or assessed value. You can also request a detailed breakdown showing how your assessed value was calculated and which comparable homes were used.
Frequently Asked Questions
Can I lower my property taxes by improving my home?
Major improvements like adding a room or finishing a basement will increase your assessed value and your taxes. Minor repairs and maintenance do not usually trigger a reassessment. If you are considering a large project, ask your assessor's office whether it will be reassessed before you start, so you know what to expect.
What happens if I disagree with the assessment after I appeal?
If your appeal is denied and you still disagree, you may be able to appeal to a county board of review or a state tax court. The process and cost vary by state. Some people hire a property tax attorney or a tax consultant to handle a second appeal, but this is usually only worth it if your home's value is very high or the error is large.
Do I have to pay property taxes if I own my home outright?
Yes. Property taxes are owed by the owner of the property, whether you have a mortgage or not. If you do not pay, the government can place a lien on your home or eventually foreclose and sell it to recover the unpaid taxes. If you cannot afford your taxes, contact your local assessor or tax collector about hardship programs or payment plans.
Why did my property tax bill go up even though my assessed value stayed the same?
Your bill can increase if the tax rate increased. This happens when your local government needs more revenue. Even if your assessed value does not change, a higher rate means a higher bill. You can find out which entity raised its rate by looking at the breakdown on your bill and comparing it to last year's bill.
How do I find out what my home is assessed at?
Call your county assessor's office or visit their website. Most assessors now publish property records online where you can search by address and see the assessed value, the last assessment date, and sometimes the comparable homes used in the valuation. You can also request a copy of your assessment from the assessor's office by mail or in person.