The Basic Formula: Assessed Value Times Tax Rate

Your property tax bill comes from one simple multiplication: the assessed value of your property times the tax rate set by your local government. The assessed value is not what you paid for the house or what it would 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 math looks like this: if your home is assessed at $300,000 and your tax rate is 1.2%, you owe $3,600 per year. If your rate is expressed as $12 per $1,000 of assessed value, the same home produces the same bill: ($300,000 ÷ $1,000) × $12 = $3,600. Both methods describe the same calculation in different language.

Key Takeaways

  • Your assessed value is determined by the county assessor and is usually lower than the price you paid or the current market value of your home.
  • Tax rates are set by local governments — county, city, and school district — and vary widely depending on where you live.
  • Most states reassess property every one to three years, and some cap how much the assessed value can increase in a single year.
  • You can request a reassessment or file a formal appeal if you believe your assessed value is too high, though deadlines and procedures vary by state.
  • Your final bill may include additional charges beyond the base tax, such as special district assessments or bond repayment fees.

How Assessed Value Is Determined

The county assessor's office assigns assessed value by looking at comparable sales in your area, the condition and age of your building, the size of the lot, and any improvements you have made. They do not inspect every home every year. Instead, most states use a cycle: some reassess all properties every year, others every three years, and a few every five years. During years when your property is not formally reassessed, your assessed value may stay the same or increase by a small percentage set by state law.

Some states, like California and Texas, have assessment caps that limit how much the assessed value can rise in a single year, even if the market value has jumped. California caps increases at 2% per year unless the property changes hands. Other states have no cap and will reassess at current market value whenever the cycle requires it. This is why two identical houses on the same street can have very different tax bills if one sold recently and one has not changed hands in decades.

You can request a reassessment outside the normal cycle if you believe the assessed value is wrong — for example, if your home was damaged by fire or if comparable sales show the value has dropped. Contact your county assessor's office to ask about the process and any deadlines.

Tax Rates and Who Sets Them

The tax rate is not one number. It is the sum of rates set by multiple taxing bodies in your area. Your county sets a rate, your city or town sets a rate, your school district sets a rate, and any special districts (fire, water, library) set their own rates. All of these add together to create your final rate. This is why property tax bills vary so much between neighborhoods and between states.

A homeowner in one county might pay 0.8% of assessed value, while a homeowner in a neighboring county pays 1.5%. Within the same county, a house in a well-funded school district might have a higher rate than one in a less-funded district. These rates are set by elected officials and approved through budget processes, usually once per year. If you want to know why your rate is what it is, your county assessor's office or tax collector can break down the rate by each taxing body.

Reassessment Cycles and When Your Bill Changes

Most states reassess property on a regular schedule. Some do it annually; others do it every three years. During a reassessment year, the assessor's office may send someone to inspect your property, or they may use sales data and public records without a visit. If you have made major improvements — added a room, replaced the roof, finished a basement — the assessed value will likely increase at the next reassessment to reflect that work.

In years when reassessment does not happen, your assessed value usually stays the same or increases by a small percentage. Some states allow the assessed value to rise by up to 3% annually without a full reassessment. Other states freeze the value until the next cycle. The rules depend entirely on your state and sometimes on your county within that state.

If you know a reassessment is coming and you believe your current assessed value is too high, you can file a formal appeal before the reassessment takes effect. The deadline to appeal is usually 30 to 60 days after you receive your assessment notice. Check your county assessor's website for the exact deadline and the form you need to file.

Additional Charges Beyond the Base Tax

Your property tax bill may include more than just the base tax calculation. Many counties add charges for special districts — fire protection, water, sewer, library, or park maintenance. These are calculated the same way (assessed value times a rate) but are listed separately on your bill. Some bills also include bond repayment fees, which are one-time or multi-year charges to pay off bonds the county or school district issued to fund construction or repairs.

Homestead exemptions and other tax breaks can reduce your bill. If you own and live in the home as your primary residence, you may be may have access to to a homestead exemption that lowers your assessed value by a set amount (often $25,000 to $50,000, depending on the state). Senior citizens, veterans, and people with disabilities may have additional exemptions. You usually have to file a form with the assessor's office to claim these — they do not happen automatically.

What Happens If You Disagree With Your Assessment

If you receive your assessment notice and believe the value is wrong, you have the right to appeal. The first step is usually an informal review with the assessor's office. Bring evidence: recent appraisals, comparable sales in your neighborhood, photographs of damage or needed repairs, or documentation of major improvements. The assessor will consider your evidence and may lower the assessment.

If the informal review does not resolve the dispute, you can file a formal appeal with your county's board of assessment appeals or assessment review board. This is a more formal process with deadlines, required forms, and sometimes a hearing. You may need to hire an appraiser or attorney, which costs money. However, if you win, you may recover the cost of the appeal in some states. Check your county's website for the appeal process, deadlines, and required documents.

How Tax Rates Change Year to Year

Even if your assessed value stays the same, your tax bill can go up or down if the tax rate changes. Rates change when local governments adjust their budgets. If a school district needs more money, it may raise its rate. If a county has a surplus, it may lower its rate. These decisions happen during the budget process, usually in spring or early summer, and take effect on the next tax bill.

Some states have tax rate caps that limit how much a rate can increase in a single year without voter approval. Others have no cap. A few states require a public vote before any rate increase. The rules vary widely, so if you want to understand why your rate changed, contact your county tax collector or the specific taxing body (school district, city, etc.) that raised it.

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 assessor estimates what your home is worth for tax purposes, which is often lower than market value. If you bought during a hot market or paid above asking price, your assessed value may be significantly less. Conversely, if you bought years ago and the market has risen, your assessed value may still lag behind current value.

Can I lower my property tax by making my house look worse?

No. The assessor looks at comparable sales and property characteristics, not the condition of your specific home in most cases. However, if your home has genuine damage — a collapsed roof, foundation problems, or fire damage — you can report it to the assessor and request a reassessment. You will need documentation, such as repair estimates or insurance claims.

What if I think my neighbor's house is worth more than mine but pays less tax?

This can happen for several reasons: your neighbor's home may have been reassessed more recently, may be in a different school district, or may have may have access to for an exemption you do not have. It can also mean your neighbor's assessment is wrong. If you believe there is an error, you can file an appeal. Bring evidence of comparable sales and ask the assessor to explain the difference.

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

Yes. Property tax is owed by the owner, whether the home is paid off or financed. If you have a mortgage, your lender may require you to pay property tax through an escrow account as part of your monthly payment. If you own outright, you pay the tax bill directly to your county tax collector.

How often should I check my assessed value?

Check it whenever you receive an assessment notice, which is usually once per year or once per reassessment cycle. You can also request a copy from your county assessor's office at any time. If you make major improvements to your home, monitor your assessed value at the next reassessment to see if it increased. If you believe it is too high, file an appeal before the deadline.