Property Tax Calculator – Estimate Your Annual Tax Bill

The headline figure is the estimated annual tax bill after applying the assessment ratio and any exemptions to market value, then applying the tax rate and adding flat special assessments. The "How the bill is built" table walks through each step from market value down to the final bill, and the 10-year projection shows how the bill compounds if the value or levy grows at the assumed annual rate.

Enter the property's market value — the sale price is usually the best starting point for a recent purchase. If your state assesses at a fraction of market value, set the assessment ratio accordingly; otherwise leave it at 100%.

Add exemptions that reduce taxable value, such as a homestead exemption. These are deducted before the rate is applied, so they lower the bill directly.

Enter the rate in whichever form your jurisdiction publishes. Some counties publish a percentage, others a mill rate or a dollars-per-$100 figure. Include fixed special assessments separately, because they are charged as flat amounts rather than as a percentage of value.

The authoritative source for all of these values is your county assessor or tax collector, and most publish current rates and parcel-level assessments online.

Taxable value = (market value × assessment ratio) − exemptions

Annual tax = taxable value × tax rate + special assessments

Mill rates convert directly to percentages:

Percentage rate = mills ÷ 10   (so 11 mills = 1.1%)

One mill is one dollar of tax per $1,000 of taxable value. The monthly escrow figure is simply the annual bill divided by twelve.

A home with a $400,000 market value in a jurisdiction that assesses at full value, with a $25,000 homestead exemption and an 11 mill (1.1%) rate:

Taxable value = 400,000 − 25,000 = $375,000

Annual tax = 375,000 × 1.1% = $4,125 → about $344 per month

Without the exemption the bill would be $4,400, so the exemption saves $275 per year. If the bill grows 2% annually, the same property costs roughly $4,930 per year a decade later.

State assessment method

Some states tax full market value, others a fixed fraction, and some cap how much assessed value can increase per year regardless of market changes.

Overlapping taxing districts

County, city, school district and special districts each set their own levy, and the total rate is the sum of all of them.

Exemptions and eligibility

Homestead, senior, disability and veteran exemptions can meaningfully lower the bill, but only if you qualify and file an application by the deadline.

Reassessment triggers

A sale, new construction, or a renovation can trigger reassessment at current market value, sometimes producing a large one-time increase.

Local budget and levy changes

Even with an unchanged assessment, a bill can rise if voters approve a bond or the taxing authority raises its rate.

• Assuming the seller's tax bill will carry over

  Many counties reassess at the sale price, so a new buyer's first full-year bill is often higher than what the seller paid.

• Confusing market value with taxable value

  Exemptions and fractional assessment ratios mean the number the rate is applied to is often well below market value.

• Treating mill rates and percentages as the same number

  A mill rate of 11 is 1.1%, not 11% — dividing by 10 converts mills to a percentage.

• Forgetting special assessments

  Flat district charges for sewer, lighting or bonds are added on top of the percentage-based tax and are easy to miss when estimating a bill.

• Not applying for an exemption you qualify for

  Homestead and other exemptions are rarely automatic; missing the filing deadline in many counties means paying the full, unreduced bill for that year.

• Look up the parcel directly on the county assessor's website for the actual assessed value and rate rather than estimating from a citywide average.
• If you recently bought the home, check whether the county reassesses at sale price — the first full-year bill may exceed the seller's.
• Apply for a homestead or other exemption as soon as you qualify; many counties require an application, not automatic enrollment.
• If the assessed value looks too high, gather comparable sales or a recent appraisal and consider filing an appeal before the deadline.
• Ask the assessor's office to itemize the levy by district (county, school, city) if you want to understand what is driving an unusually high rate.

Actual bills can differ from this estimate because of assessment caps, phased-in reassessments, mid-year rate changes, proration at closing, or additional district levies not captured in a single blended rate. Property tax rules — including assessment ratios, exemption amounts and appeal deadlines — vary by state and county, so always confirm the current figures with the local county assessor or tax collector before budgeting around this estimate.

What this calculator assumes

• The rate you enter covers all overlapping taxing districts (county, city, school, special districts).
• Exemptions reduce taxable value rather than reducing the tax bill directly.
• Special assessments are fixed dollar amounts, not value-based.
• The projection applies a constant annual growth rate.

What it does not account for

• Assessment caps and limits on annual increases, which several states apply.
• Circuit-breaker credits and income-based relief programs.
• Reassessment on sale, which can sharply change the bill in the first year of ownership.
• Tax rates applied differently by district within the same parcel.

• IRS — Topic no. 503, deductible taxes (state and local tax deduction)