Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Share of value that is taxable
Result
Value of the appeal over your hold
$4,579
Annual tax saving
$825
Net saving in year one after fees
$45
Implied property value increase
$13,750
Current annual tax bill
$6,353
Tax bill if the appeal succeeds
$5,528
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One click, a permanent link with your numbers baked in.
Got your number — what next?
Pick one, it takes 20 secondsHow to use this
- 1Enter current assessed value ($).
- 2Enter assessment you're arguing for ($).
- 3Enter combined tax rate (% of assessed).
- 4Enter assessment ratio (%) — Share of value that is taxable.
- 5Enter filing and appraisal fees ($).
- 6Enter consultant's share of first-year saving (%).
- 7Enter years you'll hold the property (years).
- 8Enter annual assessment creep back (%).
- 9Enter market cap rate (%).
- 10Read your value of the appeal over your hold on the right — it updates as you type.
- 11Hit Share to keep the scenario or send it to someone.
About this calculator
An over-assessment is a recurring overcharge, so the value of a successful appeal is not one year's saving but the saving multiplied by the years you keep the property, adjusted for how fast assessments creep back. This calculator computes the annual saving from a reduced assessed value, nets off filing fees and any consultant's contingency share, and projects the multi-year value. It also shows the effect on net operating income and, through the cap rate, the implied increase in the property's value — which is often several times the tax saving itself.
Worked example
Using the values the calculator loads with:
Inputs
- Current assessed value: 385000 $
- Assessment you're arguing for: 335000 $
- Combined tax rate: 1.65 % of assessed
- Assessment ratio: 100 %
- Filing and appraisal fees: 450 $
- Consultant's share of first-year saving: 40 %
- Years you'll hold the property: 7 years
- Annual assessment creep back: 2.5 %
- Market cap rate: 6 %
Results
- Value of the appeal over your hold: $4,579.48
- Annual tax saving: $825.00
- Net saving in year one after fees: $45.00
- Implied property value increase: $13,750.00
- Current annual tax bill: $6,352.50
- Tax bill if the appeal succeeds: $5,527.50
What each field means
Inputs
- Current assessed value ($)
- The current assessed value used in the calculation, measured in $. Starts at 385000 $ so you have a working example on load.
- Assessment you're arguing for ($)
- The assessment you're arguing for used in the calculation, measured in $. Starts at 335000 $ so you have a working example on load.
- Combined tax rate (% of assessed)
- The combined tax rate used in the calculation, measured in % of assessed. Starts at 1.65 % of assessed so you have a working example on load.
- Assessment ratio (%)
- Share of value that is taxable
- Filing and appraisal fees ($)
- The filing and appraisal fees used in the calculation, measured in $. Starts at 450 $ so you have a working example on load.
- Consultant's share of first-year saving (%)
- The consultant's share of first-year saving used in the calculation, measured in %. Starts at 40 % so you have a working example on load. Accepted range: 0–60 %.
- Years you'll hold the property (years)
- The years you'll hold the property used in the calculation, measured in years. Starts at 7 years so you have a working example on load.
- Annual assessment creep back (%)
- The annual assessment creep back used in the calculation, measured in %. Starts at 2.5 % so you have a working example on load.
- Market cap rate (%)
- The market cap rate used in the calculation, measured in %. Starts at 6 % so you have a working example on load.
Results
- Value of the appeal over your hold
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Annual tax saving
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Net saving in year one after fees
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Implied property value increase
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Current annual tax bill
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Tax bill if the appeal succeeds
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What evidence wins an assessment appeal?
Comparable sales of similar properties assessed lower, a recent arms-length purchase price below the assessment, documented condition problems, and errors in the record such as wrong square footage or bedroom count. Record errors are the easiest wins because they are factual rather than argued.
Why does the property's value go up if taxes go down?
Because income properties are priced off net operating income, and property tax is an operating expense. Removing a recurring expense raises NOI permanently, and dividing that increase by the market cap rate gives the capitalised value — often many times the annual saving.
Is a contingency-fee consultant worth it?
Frequently yes for commercial and higher-value residential, where the process is technical and the sums are large. They take a share of the first year only in most arrangements, while you keep every subsequent year — which is why the multi-year figure here matters more than the first-year net.
Can appealing raise my assessment?
In most jurisdictions a review can adjust the value in either direction, though an increase is uncommon when your evidence is sound. The real risk is filing without comparable support on a property that is genuinely under-assessed — check the comps before you draw attention.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Rental Property Cap Rate Calculator
Net operating income over price — the unlevered yield that lets you compare any two deals.
Rental Hold Period IRR Calculator
Total return across cash flow, loan paydown and sale proceeds over your hold period.
Rental Property Cash Flow Calculator
Monthly cash flow after mortgage, vacancy, and reserves.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Property Tax Appeal Value Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/property-tax-appeal-value
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/property-tax-appeal-value" target="_blank" rel="noopener">Property Tax Appeal Value Calculator — RevenueLab</a> (2026).</p>
Source: [Property Tax Appeal Value Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/property-tax-appeal-value) (2026).