Calculate your estimated annual property tax bill by entering your home value, selecting your state, and applying any exemptions.
Property tax looks mysterious until you see the formula, then it is almost mechanical: assessed value × tax rate − exemptions = tax due. The difficulty is that each piece of that formula is defined differently in every state and locality. This guide walks through the calculation step by step, the exemptions that shrink the bill, and how to estimate your own number with the calculator below.
Everything starts with market value: what a willing buyer would pay for your home today. Assessors estimate this from recent comparable sales, replacement cost, or income potential (for rentals). Some jurisdictions reassess every year; others only on a sale or on a multi-year cycle (Alabama reappraises every 4 years, for example). The more frequently values are updated, the more your bill tracks the live market.
Assessed value is market value times the assessment ratio. At one extreme, states like Hawaii and Oregon assess at 100% of market value. At the other, South Carolina assesses owner-occupied homes at 4%, West Virginia at 60%, and Wyoming residential property at roughly 9.5%. A low ratio is the structural reason some states have very low effective rates even when mill rates look high.
The rate is expressed in mills (dollars per $1,000 of assessed value) or as a percentage. A combined rate bundles the county, city, school district, and any special districts. Because the school share is usually the largest, school-levy votes move your bill the most. Enter your locality's combined rate in the calculator to get an accurate estimate — a statewide average will mislead you.
Before the rate is applied, exemptions remove value. The homestead exemption (primary residence) is the most common; seniors, disabled owners, and veterans get larger ones. Indiana adds a homestead standard deduction (the greater of $45,000 or 60% of assessed value) on top of its 1% cap. Always subtract exemptions first — they reduce the base the rate hits.
Several states cap the result. California's Prop 13 limits annual assessed-value growth to 2%. Oregon's Measure 50 caps it at 3%. Indiana's constitutional circuit-breaker caps a homestead at 1% of assessed value and refunds any excess. These caps protect long-term owners from runaway bills even in hot markets — a major reason two neighbors in identical homes can owe very different amounts.
A $300,000 home in a state assessing at 100% market value, with a 1.1% effective rate and a $20,000 homestead exemption: taxable value is $280,000; the bill is about $3,080/year ($257/month). Without the exemption it would be $3,300. Now imagine the same home in a 0.5%-rate state: about $1,500/year. The example shows the rate and exemption, not just the price, drive the bill.
If your notice shows a value above recent comparable sales, an appeal can cut your bill for years. File with the local board of review or equalization within the window (often 30–90 days), attaching 3–5 comparable sales, and any evidence of condition issues. Many owners win simply by showing the assessor's value used stale data. The appeal is free or low-cost, and a successful reduction compounds every year — which is why it is one of the highest-return tasks a homeowner can do.
Your tax is not a one-time cost; it recurs every year and usually rides inside your mortgage escrow. When lenders qualify you for a loan, they include taxes and insurance in the debt-to-income math, so a high-tax area can shrink the loan you qualify for. Budgeting the true monthly tax — not the seller's old figure — prevents a nasty surprise after closing. The payment calculator (linked below) turns the annual estimate into the monthly number your budget feels.
Market value — the price a willing buyer would pay today. Assessed value — market value times the assessment ratio. Mill — $1 of tax per $1,000 of assessed value. Homestead exemption — a removal of primary-residence value before tax. Circuit breaker — a cap or refund that limits tax relative to income.
States continually tinker with the calculation: proposing assessment-cap changes, exemption increases, or levy limits. California's Prop 13 and similar caps are periodically challenged; Indiana's circuit-breaker is reviewed in budget cycles. Because the formula is statutory or constitutional, any change affects your bill — so follow your state legislature and local board meetings, not just the federal news.
Do not use a statewide average rate for your estimate — rates vary block by block. Do not forget to claim exemptions after moving or inheriting a home; they rarely carry over automatically. And do not assume last year's bill is this year's: reassessment and new levies change it. The calculator below handles the math; you supply the right local rate and exemptions.
Claim every exemption you qualify for, appeal the assessed value if comparable sales are lower, and watch local levy votes. If you are house-hunting, run the number for each candidate address — the tax difference can change which home is truly affordable. Use the calculator below to see how value, rate, and exemption interact before you commit.
What is the difference between market value and assessed value? Market value is what the home would sell for; assessed value is market value times your state's assessment ratio, and the rate is applied to it.
Why is my effective rate lower than the mill rate? Exemptions, low assessment ratios, and caps all reduce the base or the result, so the effective rate on market value is usually far below the headline mill rate.
How do I find my local rate? Your county assessor or tax collector publishes the combined mill rate; your assessment notice also shows it. Enter that, not a state average, in the calculator.
Are property taxes deductible? They may be deductible on federal Schedule A if you itemize, subject to the SALT cap; consult a tax professional for your situation.
Does the calculator replace my assessment? No. It estimates your bill from your inputs; your official bill comes from the assessor using your specific values and exemptions.
Your annual assessment notice is the document that drives the whole calculation, yet most owners skim it. It shows your home's assessed value, your taxable value after exemptions, the local tax rate, and the resulting bill. Check the assessed value first: if it is higher than recent comparable sales, you have grounds to appeal. Note the deadline — the window to challenge is short, often 30 to 90 days — and it will not reopen later.
Also confirm that every exemption you qualified for is listed. Owners are frequently billed at the non-exempt rate because a senior, disability, or veteran exemption was never applied or lapsed after a refinance. If the notice shows the wrong rate district, call the assessor; an error there flows straight into a higher bill. Treat the notice as a yearly check-up, not junk mail.
The same formula behaves differently by property type. A rental or investment home gets no homestead exemption and may carry depreciation recapture at sale, so its effective tax is higher. A new-construction home is often taxed on a preliminary value until the first full reassessment, which can jump the bill in year two or three. A vacation or second home is taxed at the non-homestead rate and has no primary-residence break. Understanding your home's category tells you which exemptions and caps you can expect — and what the calculator below should assume.
Two identical homes on the same block can owe very different tax when one owner claims an exemption the other never filed, or when one successfully appealed an inflated assessment. The bill is not purely a function of the building — it is the building times the rules times the owner's actions. That is good news: a few hours of exemption filing and a careful appeal can permanently lower what you owe, and the calculator below shows the dollar impact of each choice you make.
Enter your home value, select your state, and see your estimated annual property tax.
This free calculator helps you estimate your annual property tax bill in three simple steps:
Click "Calculate My Property Tax" to see your estimated annual bill, monthly payment, and how you compare to the national average. You can also compare tax rates across all 50 states.