Property Tax Calculator — estimate your annual bill

A property tax calculator turns three numbers you can find in about five minutes — your home's assessed value, your local millage rate, and any exemption you qualify for — into the number that actually matters: what you'll owe (or what your lender will collect through escrow) this year. Property tax is one of the few taxes that never disappears, whether you're mortgage-free or thirty years into a loan, and it quietly grows every time your local assessor revalues the neighborhood.

At Arb Digital we build tools like this one because homeowners, buyers, and small landlords ask us the same question constantly during site and content work for real-estate and finance clients: "what will my property tax actually be?" This calculator gives you a fast, editable estimate — not a bill — so you can budget with confidence before you talk to your assessor, lender, or accountant.

What This Property Tax Calculator Does

You enter your home's assessed value, your local tax rate (also called a millage rate), and the dollar value of any homestead or other exemption you receive. The calculator subtracts your exemption from the assessed value to get your taxable assessed value, then applies your rate to produce an annual property tax figure. From there it breaks the number down into a monthly escrow amount (what a mortgage lender would typically collect each month to cover the bill), your effective rate compared against the home's market value, and the dollar amount your exemption is saving you every year.

Because every input box is editable, you can immediately test scenarios: what happens if your assessment jumps 8% at the next reappraisal, what a homestead exemption is actually worth in dollars, or how your rate compares to a county you're considering moving to.

How to Use It

1. Find your assessed value. This is on your county assessor's website or your most recent property tax notice — it is usually not the same as your home's market value.
2. Look up your millage or tax rate. Your county, city, and school district each set a piece of this; your tax bill or assessor's site usually lists the combined rate as a percentage.
3. Enter any exemption. Homestead, senior, veteran, or disability exemptions reduce your taxable assessed value — enter the dollar amount, not the percentage.
4. Enter your market value (optional). This lets the calculator show your effective rate against what the home is actually worth, which is the number most useful for comparing markets.
5. Click Calculate to see your estimated annual bill, monthly escrow, and exemption savings update instantly.

The Formula / How It's Calculated

Property tax math is simpler than most people expect. First, your taxable assessed value is your assessed value minus any exemption: Taxable Assessed Value = Assessed Value − Exemption. Second, your annual tax is that taxable value multiplied by your local rate: Annual Tax = Taxable Assessed Value × Tax Rate. If your county quotes a millage rate instead of a percentage — for example, "22 mills" — that simply means $22 of tax per $1,000 of assessed value, which is mathematically the same as a 2.2% rate. The IRS allows most homeowners to deduct property tax as part of the state and local tax (SALT) deduction on a federal return, subject to a $10,000 combined cap, which is a separate calculation from what you owe locally.

Assessed Value vs. Market Value: Why They're Different

One of the most common points of confusion in property tax is the gap between assessed value and market value. Market value is what a buyer would realistically pay for your home today. Assessed value is a number your county assessor's office assigns for tax purposes, and in most states it is not the same as market value — it might be a percentage of market value (an "assessment ratio"), or it might lag behind market value because reassessments only happen every one to five years depending on your jurisdiction. Some states cap how fast assessed value can rise each year even when market prices spike, which is why two nearly identical homes on the same street can carry very different tax bills if one changed hands recently and was reassessed at the new sale price. Understanding which number your bill is actually based on is the single biggest source of "why is my neighbor's tax bill lower than mine" confusion, and it's exactly why this calculator separates the two.

Understanding Millage Rates

A mill is one-thousandth of a dollar, so a millage rate of 20 mills means $20 of tax for every $1,000 of taxable assessed value — or 2.0% expressed as a percentage. Your total rate is usually a stack of several smaller rates layered together: a county rate, a city or township rate, a school district rate, and sometimes special district rates for things like fire protection, libraries, or water. Each of these is voted on or set independently, which is why total rates can vary sharply even between neighboring towns. When you're comparing property tax burdens across areas — say, for a relocation or an investment property purchase — the combined millage rate is the number to compare, not just the county rate alone. Many county treasurer or assessor websites publish the full rate breakdown, and it's worth pulling that document once so you know exactly what's driving your bill.

How to Appeal Your Assessment

If your calculated effective rate looks high relative to comparable homes, or if your assessed value climbed sharply after a reassessment, you generally have the right to appeal. Most jurisdictions publish an appeal window — often 30 to 90 days after assessment notices go out — and the process typically involves filing a form with your county's board of equalization or assessment review board along with evidence: recent comparable sales, an independent appraisal, or photos documenting condition issues the assessor may not have accounted for (deferred maintenance, an outdated kitchen, foundation problems). Appeals that succeed usually hinge on hard comparables, not general complaints about affordability. It costs nothing to request your property's assessment record and compare it against three or four similar homes that sold recently in your area — that single step catches most over-assessments before you ever need to file formally.

How Escrow Accounts Actually Work

If you have a mortgage, there's a good chance you never write a check directly to your county for property tax — your lender collects it for you through an escrow account. Every month, part of your mortgage payment is set aside specifically for taxes and homeowners insurance, and the lender pays the county (and your insurer) on your behalf when the bills come due. This is where the monthly escrow figure from this calculator becomes genuinely useful: it shows you roughly what your lender should be collecting each month just for the tax portion, separate from principal and interest. If your mortgage statement shows a materially different monthly tax escrow, it's worth asking your servicer for an escrow analysis, since these accounts are recalculated annually and can run short or build up a surplus depending on how accurately last year's estimate matched the real bill. A shortfall typically means a higher payment next year to catch up; a surplus is usually refunded or applied forward. Homeowners without a mortgage, or those who've paid theirs off, pay the county directly — usually in one or two installments per year — and should budget for the full amount rather than relying on a monthly escrow habit that no longer applies.

How State and Local Rules Change the Picture

Property tax is almost entirely a state and local matter in the US, which means the rules this calculator generalizes can vary sharply depending on where you live. Some states cap annual increases in assessed value for owner-occupied homes, which can create a large and growing gap between assessed and market value the longer you own a property — a homeowner who's lived in a house for fifteen years in a capped state may have an assessed value far below what the home would sell for today. Other states reassess every year and pass market swings straight through to your bill. Exemption programs also vary widely: some states offer generous homestead exemptions automatically, others require an annual application, and many offer additional relief for seniors, veterans, or disabled homeowners that isn't applied unless you specifically request it. Because this calculator uses illustrative national figures, always cross-check your county assessor's site or your most recent tax notice for the numbers that actually apply to your property before making a financial decision based on the estimate.

Common Mistakes to Avoid

• Confusing assessed value with market value. Plugging in your Zillow estimate instead of your actual assessed value will throw off the whole calculation.
• Forgetting to apply an exemption you already qualify for. Homestead exemptions in particular are sometimes not automatically renewed after a refinance or a name change on the deed.
• Assuming your rate is fixed. Millage rates change most years as local budgets, school levies, and bond measures are approved or voted down.
• Ignoring special assessments. Some bills include separate line items — like a sidewalk or sewer assessment — that aren't part of the standard millage calculation.
• Not budgeting for reassessment jumps. If your area is due for a reappraisal and prices have risen sharply, your next bill could be meaningfully higher than this year's.

Related Free Tools From Arb Digital

Property tax is just one piece of your overall tax and homeownership picture. Pair this calculator with our mortgage interest deduction calculator to see how much of your home costs are deductible, or our standard vs. itemized deduction calculator to check whether itemizing (which is required to claim property tax as a deduction) even beats the standard deduction for your situation. Self-employed homeowners should also check the home office deduction calculator, and anyone estimating their full tax year should try our income tax calculator and self-employment tax calculator. Browse the full free online tools hub for more.

Frequently Asked Questions

This tool provides general estimates for educational purposes only and is not financial, tax, legal, or medical advice. Figures are illustrative; consult a licensed professional for decisions.