Property taxes fund local government services and are calculated by multiplying your home's assessed value by your local tax rate. Here's how the system works, why your bill can change, and what you can do if your assessment seems off.
Property taxes are annual taxes that local governments charge on real estate. Unlike federal income taxes, which fund national programs, property taxes stay local. They pay for the schools, roads, fire departments, and public parks in your specific town or county.
If you own a home, you are most likely paying property taxes every year. Some homeowners pay them directly to their local taxing authority twice a year. Others pay through an escrow account managed by their mortgage servicer, which collects a portion of the estimated annual tax bill with each monthly mortgage payment.
How property taxes are calculated
Your property tax bill comes down to two numbers: your assessed value and your local tax rate. Multiply them together and you get your annual bill.
If your home is assessed at $300,000 and your local tax rate is 2%, your annual bill is $6,000 — about $500 a month if your mortgage servicer collects it through escrow.
What is assessed value?
Your assessed value is the dollar amount your local assessor assigns to your home for tax purposes. It is not necessarily the same as what your home would sell for on the open market.
Assessors use a process called mass appraisal. Rather than visiting each property individually, they estimate the value of thousands of homes at once using recent sales data, neighborhood trends, and property characteristics like square footage, lot size, age, and condition. The results are reasonably accurate for most homes, but the process is not perfect.
Different jurisdictions handle the relationship between assessed value and market value differently. Some states require assessed value to equal 100% of estimated market value. Others assess at a percentage, such as 35% or 70%, and adjust the tax rate accordingly. The end tax bill is the same either way, but knowing your jurisdiction's rules helps you understand whether your assessment is in range.
Assessors typically update values on a schedule. Some counties reassess annually. Others do it every few years. In between reassessment cycles, your assessed value may stay flat even if your home's actual market value has moved up or down.
What is the tax rate?
Your tax rate, sometimes called the mill rate or millage rate, is set by your local government based on how much revenue it needs to fund public services. One mill equals $1 of tax for every $1,000 of assessed value. A mill rate of 20 mills equals a 2% effective tax rate.
Multiple local taxing bodies typically layer their rates together. Your total bill usually reflects rates set separately by the county, the municipality, the school district, and any special districts for things like libraries or fire services. Each entity sets its rate independently, and all of them appear on your final tax bill.
Why property taxes go up
Property taxes can increase for two reasons, and often both happen at the same time.
The first is an increase in your assessed value. When your county reassesses properties and finds that home values in your neighborhood have risen, your assessed value will likely go up too, and your bill will follow.
The second is an increase in the tax rate. Even if your assessed value stays flat, your local government can raise the mill rate when it needs more revenue to fund services or cover budget shortfalls.
In many markets over the past several years, both factors have moved together. Assessed values have tracked rising home prices, and local governments have held or increased their rates. For a lot of homeowners, the combined effect has been a significant jump in annual property tax bills.
What happens if your assessment seems too high?
Property assessors make mistakes. Market data gets misapplied. Properties with unique characteristics or conditions are sometimes valued higher than what comparable homes actually sell for nearby.
Most jurisdictions give homeowners the right to challenge their assessed value through a formal appeal process. The process typically works like this:
- 1File a complaint with your county's review board before the filing deadline.
- 2Submit evidence — typically comparable sales showing similar homes sold for less than your assessed value implies.
- 3The board reviews your case, sometimes in a scheduled hearing, and issues a decision.
- 4If the board agrees your assessment was too high, your value is reduced and future bills reflect the change.
Filing deadlines are strict and vary by county. Missing the window generally means waiting until the next assessment cycle to appeal.
A successful appeal does not just reduce one year's bill. It lowers your assessed value going forward, which means the savings compound every year until the next reassessment.
Homestead exemptions and other reductions
Many states offer exemptions that reduce the taxable portion of your home's assessed value if it is your primary residence. These are called homestead exemptions. Some states also offer additional exemptions for seniors, veterans, and people with disabilities.
Exemptions vary widely by state and county. In some places they are applied automatically once you own and occupy the home. In others you have to file an application. If you are not sure whether you are receiving every exemption you qualify for, your county assessor's office can confirm.
The bottom line
Property taxes are calculated by multiplying your assessed value by your local tax rate. They fund local government services and for most homeowners represent one of the largest recurring costs of ownership after the mortgage itself.
If your assessed value is higher than what comparable homes in your area are actually selling for, you may be paying more than you should. Most homeowners have the right to appeal, and a successful appeal reduces your bill not just for one year but for every year until the next reassessment.