Enter your home's assessed value, your annual tax rate (mill rate ÷ 10), and any exemption you qualify for. You'll get your estimated annual property tax and its monthly equivalent.
How property tax is calculated
Property tax is refreshingly simple math applied to a slightly slippery number. The formula is just taxable value × rate — the slippery part is the taxable value. It starts from your assessed value (set by the local assessor, and often lower than market value), then subtracts any exemptions you've claimed, like a homestead exemption on your primary residence. The rate itself is set by your county, city, and school district combined, which is why identical houses one town apart can owe very different bills.
The formula
Annual tax = (Assessed value − Exemptions) × Rate ÷ 100
Rate is the annual tax rate as a percentage. If your locality quotes a mill rate, divide it by 10 to get the percentage: 1 mill = $1 of tax per $1,000 of value = 0.1%.
Worked example
A home assessed at $250,000 with a $25,000 homestead exemption in a district charging 1.2% (that's 12 mills):
Tax = (250,000 − 25,000) × 0.012 = $2,700 per year, or $225 per month if your lender escrows it.
Mills, assessment ratios, and other local quirks
Mill rates sound arcane but are just a unit: one mill is one-thousandth, so a 25-mill levy is 2.5%. Where it gets genuinely confusing is that some states don't tax the full assessed value — they apply an assessment ratio first (say, taxing only 40% of value), or cap annual assessment growth so long-time owners are taxed on numbers far below market. The practical advice: pull the actual taxable value and combined rate from your most recent tax notice and plug those in here. And if your assessment looks high compared to your neighbors' — appeal it. It's usually free, and the worst outcome is a polite no.
Frequently asked questions
How is property tax calculated?
Multiply your taxable value (assessed value minus any exemptions) by your local tax rate. A $250,000 assessment with a $25,000 exemption at a 1.2% rate owes ($250,000 − $25,000) × 0.012 = $2,700 per year. Rates are set locally, so the same house can owe very different amounts in different counties.
What is a mill rate?
A mill is one-tenth of a percent: $1 of tax per $1,000 of taxable value. So a mill rate of 12 mills equals a 1.2% tax rate. If your county quotes mills, divide by 10 to get the percentage this calculator expects — 25 mills becomes 2.5%.
What's the difference between assessed value and market value?
Market value is what your home would sell for; assessed value is the number the tax office actually taxes, and it's often lower. Some states assess only a fraction of market value (an assessment ratio), and many cap how fast assessments can rise each year. Always use the assessed value from your tax notice here, not your Zillow estimate.
What is a homestead exemption?
It's a reduction in taxable value for a home you live in as your primary residence — for example, a $25,000 homestead exemption means you're taxed as if the home were worth $25,000 less. Many states offer extra exemptions for seniors, veterans, or people with disabilities, but most require you to apply; they aren't automatic.
How can I lower my property taxes?
First, claim every exemption you qualify for. Second, check your assessment for errors (wrong square footage, extra bathrooms that don't exist) — you can appeal it, and a meaningful share of appeals succeed. Third, compare your assessment to similar nearby homes; a clearly higher number is good evidence in an appeal.