Property Tax Appeal Calculator: Estimate Your Savings

This property tax appeal calculator shows what a lower assessed value could be worth before you spend time on an appeal. Enter the value on your notice, the value you think is fair, your tax rate and your costs. You will see the yearly savings, the total over the years you choose, and what is left after costs.

How to use this calculator

1. Current assessed value. Copy it from your latest assessment notice or your county’s online property record.
2. Target assessed value. This is the value you believe your evidence supports. Start with recent sales of similar nearby homes. If your area assesses at less than 100% of market value, multiply that market value by the local assessment ratio first.
3. Combined tax rate. Add the rates for every taxing unit on your bill. If your bill uses mills, divide by 10 to get a percent (25 mills = 2.5%).
4. Years. How long the lower value is likely to last. Some states apply a win to one year only, so 1 is the safe choice if you are not sure.
5. Cost of appealing. Include filing fees, an appraisal if you order one, and any other out-of-pocket costs. If you file on your own, your costs may be small.

How this calculator works

The reduction is your current assessed value minus your target value, never below zero. Yearly savings equal that reduction times your tax rate. Total savings multiply the yearly figure by the number of years (rounded to a whole number, at least 1). Net savings subtract your costs, so the result can be negative.

Reduction      = Current assessed − Target assessed (not below $0)
Yearly savings = Reduction × Tax rate ÷ 100
Total savings  = Yearly savings × Years
Net savings    = Total savings − Appeal cost

What it assumes:

• The default inputs ($320,000 current value, $295,000 target, 1.2% rate, 2 years, $0 cost) are hypothetical examples.
• Your tax rate stays the same each year, and the whole reduction is taxed at one combined rate.
• Exemptions are not changed by the appeal, and your value is not raised by the board.
• Interest on refunds, the value of your time and later reassessments are ignored.

Worked examples

Example 1: the default inputs

Hypothetical example: your notice shows $320,000, you believe $295,000 is fair, your combined rate is 1.2%, the lower value would last 2 years, and you spend nothing.

1. Reduction: $320,000 − $295,000 = $25,000
2. Yearly savings: $25,000 × 1.2 ÷ 100 = $300
3. Total savings: $300 × 2 = $600
4. Net savings: $600 − $0 = $600

Example 2: when costs eat the savings

Hypothetical example: a $320,000 assessment, a $300,000 target, a 2% rate, a win that applies to 1 year only, and a $500 appraisal.

1. Reduction: $320,000 − $300,000 = $20,000
2. Yearly savings: $20,000 × 2 ÷ 100 = $400
3. Total savings: $400 × 1 = $400
4. Net savings: $400 − $500 = −$100

Here, paying for an appraisal would cost more than the appeal saves. Free evidence, such as comparable sales and photos, could change that.

What your result means

A positive net figure means the appeal could pay off if you win. A negative figure means your costs are larger than the likely savings. The result assumes you win the full reduction, which is never guaranteed, so treat it as a best case.

Rules that change the answer

• Deadlines. In Texas, the usual deadline to protest is May 15 or 30 days after the appraisal district mails your notice, whichever is later (Texas Comptroller). California’s regular filing period runs from July 2 to September 15 or November 30, depending on the county (California State Board of Equalization). Miss the window and the savings are zero.
• How long a win lasts. Texas review board decisions bind only that tax year, and California decline-in-value appeals apply only to the year filed. Enter 1 year in those cases unless you plan to appeal again.
• Fractional assessments. New York explains that if your town assesses at 90% of market value, a $100,000 home should be assessed at $90,000 (New York State Department of Taxation and Finance). Convert your target value the same way.
• Taxes are not set by the assessor. New York and Texas both note that the board decides value, not tax rates. High rates alone are not grounds for an appeal.
• Paying during the appeal. California’s guide says to pay on time while an appeal is pending, and a reduction brings a refund with interest.

Common mistakes

• Entering market value as the target when your area assesses at a fraction of market value.
• Using only the county rate instead of the combined rate.
• Assuming a win lasts forever. Many places reassess each year.
• Forgetting costs such as a paid appraisal.
• Waiting until after the deadline to gather evidence.

Limits and when to get help

This tool cannot tell you whether your appeal will succeed or what value a board will accept. It does not know your local deadline, how exemptions or caps interact with a new value, or whether your state offers further appeals. Start with your assessment notice and your county assessor’s office; many assessors will review an obvious error informally.

For a step-by-step plan, read how to appeal a property tax assessment. To estimate your whole bill, use the property tax calculator. For a complex or high-value case, a licensed appraiser or a property tax attorney can help.