Compare supported values with explicit tax assumptions. This is an unofficial analysis, not an appeal filing.
Review previous saved data on this device
Value and tax assumptions
USD inputs accept up to 1,000,000,000,000 with two decimal places. Rates and ratios accept eight decimal places; horizon and cycle use whole years from 1 to 50.
Use the selected basis. A supported estimate is not an appraisal.
Use the selected basis. A supported estimate is not an appraisal.
The entered rate applies to taxable value only. Select the unit explicitly.
Applied only to market-value inputs; enter the ratio from your notice. The 100% default is an editable assumption.
The same exemption is subtracted on both sides; taxable value has a zero floor. Already-taxable inputs are not reduced again.
Separate charges unrelated to assessed value remain unchanged.
Actual bill and filing costs
Optional independent evidence. Assumption edits never overwrite this field.
Your estimate; no local fee or typical appraisal cost is inferred.
Your estimate; no local fee or typical appraisal cost is inferred.
Supported range and hypothetical totals
Optional paired bounds in the target basis. The interval must contain the target value.
Optional paired bounds in the target basis. The interval must contain the target value.
Hypothetical totals assume the change continues under your chosen growth and cycle inputs. They do not forecast future bills or appeal outcomes.
Cost-to-cure evidence
Repair cost is not automatically a value loss. Deduct only a supported market-value adjustment that is absent from your target.
Labels, notes and filenames stay in this tab session and are excluded from saved state and shared links.
Potential annual tax reduction if assessed value is changed
Unavailable
Conditional on approval, the entered rate and unchanged fixed charges. A negative result is a tax increase, not savings.
Simplified model: caps, changing exemptions, multiple districts and local legal rules are not modeled.
Proposed total annual taxUnavailable
Value reduction on the same assessed basisUnavailable
Supported annual savings rangeUnavailable
Estimated cost recoveryUnavailable
Evidence completeness
Current and proposed annual tax in USD
Savings under valuation uncertainty
Hypothetical cumulative differences
Hypothetical totals assume the change continues under your chosen growth and cycle inputs. They do not forecast future bills or appeal outcomes.
Year 1
Year 3
Year 5
Year 10
Cumulative difference minus costs (USD)
Comparable Analysis
Sales and assessment-equity comparisons are separate worksheets. They do not provide an appraisal or legal conclusion.
Area supports descriptive per-area comparisons only; it never creates an automatic value adjustment.
Sales and assessment-equity comparisons are separate worksheets. They do not provide an appraisal or legal conclusion.
Row
Value basis
Sale date (YYYY-MM-DD) / tax year (YYYY)
Area (square feet)
Property type
Value per square foot
Supported adjusted value (USD)
Completeness
Average of complete supported rows (USD):
Filing Guide
Unknown local procedure. Confirm your authority, tax year, valuation date, filing window, fee, form and evidence rules locally. This calculator cannot determine a deadline.
Evidence checklist
These references explain tax arithmetic and examples of evidence. They do not establish rules for your property.
References reviewed 2026-10-20; local procedure remains unverified.
Unofficial property tax analysis
Labels, notes and filenames stay in this tab session and are excluded from saved state and shared links.
Only filenames are read in this tab session. No file content is read or uploaded; no document is attached to an appeal.
Review the link before sharing
For education only; not tax, legal or filing advice. Confirm requirements with your local authority or a qualified adviser.
Property Tax Appeal CalculatorFor education only; not tax, legal or filing advice. Confirm requirements with your local authority or a qualified adviser.USD inputs accept up to 1,000,000,000,000 with two decimal places. Rates and ratios accept eight decimal places; horizon and cycle use whole years from 1 to 50.Filing plus professional costs divided by a positive annual tax difference. This is financial break-even, not a likelihood of approval.Market value is converted by the entered ratio. Assessed value is before exemptions; taxable value is after them.Compare supported values with explicit tax assumptions. This is an unofficial analysis, not an appeal filing.Appeal CalculatorComparable AnalysisFiling GuideCalculator sectionsValue and tax assumptionsCurrent value basisTarget value basisMarket valueAssessed value before exemptionsTaxable value after exemptionsCurrent value (USD)Supported target value (USD)Use the selected basis. A supported estimate is not an appraisal.Tax rateRate unitPercent (%)Mills ($1 per $1,000)The entered rate applies to taxable value only. Select the unit explicitly.Assessment ratio (%)Applied only to market-value inputs; enter the ratio from your notice. The 100% default is an editable assumption.Exemption in assessed dollars (USD)The same exemption is subtracted on both sides; taxable value has a zero floor. Already-taxable inputs are not reduced again.Unchanged fixed charges (USD/year)Separate charges unrelated to assessed value remain unchanged.Actual bill and filing costsActual current annual bill (USD)Optional independent evidence. Assumption edits never overwrite this field.Use modeled current billFiling cost estimate (USD)Professional cost estimate (USD)Your estimate; no local fee or typical appraisal cost is inferred.Supported range and hypothetical totalsSupported low value (USD)Supported high value (USD)Optional paired bounds in the target basis. The interval must contain the target value.Cost recovery horizon (years)Hypothetical savings growth per cycle (%)Hypothetical cycle length (years)Explore the supported rangeHypothetical totals assume the change continues under your chosen growth and cycle inputs. They do not forecast future bills or appeal outcomes.Cost-to-cure evidenceTreatment of defectsAlready reflected in target / no additional deductionDeduct a supported market-value adjustmentSupported market-value deduction (USD)Estimate source and double-count checkRepair cost is not automatically a value loss. Deduct only a supported market-value adjustment that is absent from your target.I have support for this adjustment and it is not already included in the target.Any defect adjustment is a user-supported assumption, not an automatic cost-to-cure appraisal.Potential annual tax reduction if assessed value is changedConditional on approval, the entered rate and unchanged fixed charges. A negative result is a tax increase, not savings.Simplified model: caps, changing exemptions, multiple districts and local legal rules are not modeled.Proposed total annual taxValue reduction on the same assessed basisSupported annual savings rangeEstimated cost recoveryEvidence completenessCompleteness describes the worksheet, not admissibility, value, approval likelihood or a legal right to a reduction.Current and proposed annual tax in USDCurrent calculation detailsProposed calculation detailsSavings under valuation uncertaintyThe shaded interval is the user-supported value range. The dashed reference is total costs divided by the chosen horizon; growth is excluded from that reference.CurrentProposedValue basisEntered value (USD)Ad-valorem tax (USD/year)Total annual tax (USD)Annual tax (USD)Reference current bill (USD)Actual bill minus modeled current tax (USD)The current reference is the modeled tax; no actual bill was supplied.Savings use the independently entered actual bill:Reconcile this difference with the bill. It may include charges or rules outside this simplified model.Signed annual tax difference (USD)Modeled current minus proposed tax (USD)Annual savings / increase (USD)Annual cost recovery reference (USD)Supported target value (USD)Not inferredNo common assessed basisNot enteredNo recovery from positive savingsNo costs enteredyearsYearCumulative tax difference (USD)Cumulative difference minus costs (USD)Hypothetical cumulative differencesSubject area (square feet)Area supports descriptive per-area comparisons only; it never creates an automatic value adjustment.Subject target value per square footMarket salesAssessment equityUse sale dates in YYYY-MM-DD format, property types and supported adjustments. No price-per-area size correction is inferred.Enter assessment values for the same tax year (YYYY), property types and supported adjustments. Local assessment-equity rules still need review.Sales and assessment-equity comparisons are separate worksheets. They do not provide an appraisal or legal conclusion.ComparableSale / assessment value (USD)Area (square feet)Sale date (YYYY-MM-DD) / tax year (YYYY)Property typeSupported adjustment (USD)I have evidence for the value and the adjustment, including a zero adjustment.Supported adjusted value (USD)Value per square footCompletenessCompleteIncompleteRowComplete comparable rowsAverage of complete supported rows (USD)Use supported average as targetComplete rows form an evidence worksheet, not an appraisal, approval forecast or legal conclusion.Use the average only with the matching target basis. No automatic size adjustment is made.Optional private export notesIdentifying label (optional)Evidence notes (optional)Attachment filenames (optional)Only filenames are read in this tab session. No file content is read or uploaded; no document is attached to an appeal.Labels, notes and filenames stay in this tab session and are excluded from saved state and shared links.Include identifying labels, notes and filenames in this Copy, CSV or Print exportIdentifying labels, notes and filenames are omitted. Original documents must be supplied separately.Unknown local procedure. Confirm your authority, tax year, valuation date, filing window, fee, form and evidence rules locally. This calculator cannot determine a deadline.Evidence checklistChecked evidence itemsAssessment notice and tax year reviewedBill, exemptions and separate fixed charges reviewedSupported target and valuation date documentedComparable dates, area, type and adjustments supportedDefect evidence reviewed for double countingLocal authority, procedure, fees and filing window confirmedThese references explain tax arithmetic and examples of evidence. They do not establish rules for your property.New York Tax Department: tax calculation exampleCalifornia BOE: assessment appeal evidence and possible outcomesReferences reviewed 2026-10-20; local procedure remains unverified.Unofficial property tax analysisPrint unofficial analysis packetCurrencyUSD amounts round to cents at assessed-value and tax boundaries. Hypothetical annual cash flows round to cents; displayed values may be shorter than exported numbers.Review the link before sharingInclude the displayed financial assumptions and comparable values in this linkThis link includes current and target values, basis, rate and unit, ratio, exemption, charges, actual bill, costs, supported range, projection inputs and comparable values. Anyone with it can read them.This link opens the calculator without financial inputs. Select the checkbox only if you want those values in the link.Copy reviewed linkCancelEnter valid financial inputs before including them in a link.Copied.Copy failed; select the text and copy it manually.UnavailableEnter valid values in the stated units and precision.Enter valid values and an explicit basis for both sides.Enter a nonnegative rate and select Percent or Mills.Use nonnegative USD amounts with no more than two decimal places.A deduction requires a market-value target and cannot exceed the supported target or low bound.Confirm support and no double counting before deducting a market-value adjustment.Enter both supported bounds or leave both blank.The supported bounds must include the target value and remain nonnegative.Use whole horizon/cycle years from 1 to 50 and growth from -100% to 100%.The chosen assumptions exceed the representable financial range.The chart is unavailable. The complete calculation tables remain available.Prior values were imported using assessed-current and market-target bases. Review them. Preset defects, the earlier checklist, unsupported comparable adjustments and private labels were not imported.Saved values could not be read. Reset to save new values.Saved data changed in another tab. Reload before saving or resetting.Input format: 1.234,56 for amounts and 0,001 for a decimal rate.Input format: 1,234.56 for amounts and 0.001 for a decimal rate.
3 min read5 steps6 terms2 examples6 FAQsA = V × q/100; B = max(0, A − E)
Compare supported values with explicit tax assumptions.
Market value is converted by the entered ratio. Assessed value is before exemptions; taxable value is after them.
2
Rate unit
The entered rate applies to taxable value only. Select the unit explicitly. Percent (%): r/100. Mills ($1 per $1,000): m/1000.
3
Actual current annual bill (USD)
Optional independent evidence. Assumption edits never overwrite this field. Your estimate; no local fee or typical appraisal cost is inferred.
4
Evidence completeness
Completeness describes the worksheet, not admissibility, value, approval likelihood or a legal right to a reduction.
5
Review the link before sharing
This link opens the calculator without financial inputs. Select the checkbox only if you want those values in the link.
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Reference
Formula & Methodology
3 formulas▸
Value basis
A = V × q/100; B = max(0, A − E)
Market value is converted by the entered ratio. Assessed value is before exemptions; taxable value is after them. The same exemption is subtracted on both sides; taxable value has a zero floor. Already-taxable inputs are not reduced again.
Tax rate
T = B × r/100 + F; T = B × m/1000 + F
The entered rate applies to taxable value only. Select the unit explicitly.
Signed annual tax difference (USD)
S = C − P; Y = K/S (S > 0)
Filing plus professional costs divided by a positive annual tax difference. This is financial break-even, not a likelihood of approval.
Reviewer: Calculover Editorial Review - High-risk source and limitation review
Last reviewed: 2026-10-20
Last verified: 2026-10-20
Data effective: 2026-10-20
Methodology
Market value is converted by the entered ratio. Assessed value is before exemptions; taxable value is after them. The entered rate applies to taxable value only. Select the unit explicitly. USD amounts round to cents at assessed-value and tax boundaries. Hypothetical annual cash flows round to cents; displayed values may be shorter than exported numbers.
Assumption: Conditional on approval, the entered rate and unchanged fixed charges. A negative result is a tax increase, not savings.
Assumption: Any defect adjustment is a user-supported assumption, not an automatic cost-to-cure appraisal.
Assumption: Hypothetical totals assume the change continues under your chosen growth and cycle inputs. They do not forecast future bills or appeal outcomes.
Limitations & guidance
Simplified model: caps, changing exemptions, multiple districts and local legal rules are not modeled.
Local procedure has not been verified. Confirm your authority, tax year, valuation date, filing window, fee, form and evidence rules locally. This calculator cannot determine a deadline.
Completeness describes the worksheet, not admissibility, value, approval likelihood or a legal right to a reduction.
Professional guidance: For education only; not tax, legal or filing advice. Confirm requirements with your local authority or a qualified adviser.
Value basis ↗Market value is converted by the entered ratio. Assessed value is before exemptions; taxable value is after them.
Assessment ratio (%) ↗Applied only to market-value inputs; enter the ratio from your notice. The 100% default is an editable assumption.
Exemption in assessed dollars (USD) ↗The same exemption is subtracted on both sides; taxable value has a zero floor. Already-taxable inputs are not reduced again.
Estimated cost recovery ↗Filing plus professional costs divided by a positive annual tax difference. This is financial break-even, not a likelihood of approval.
Evidence completeness ↗Completeness describes the worksheet, not admissibility, value, approval likelihood or a legal right to a reduction.
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Scenarios
Real-World Examples
2 worked examples▸
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Case A
Current and proposed annual tax in USD
Result
Signed annual tax difference (USD): USD 625.00
Value basis Taxable value after exemptionsCurrent value (USD) USD 200,000.00Supported target value (USD) USD 150,000.00Tax rate 12.5 Mills ($1 per $1,000)
Conditional on approval, the entered rate and unchanged fixed charges. A negative result is a tax increase, not savings.
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Case B
Current and proposed annual tax in USD
Result
Signed annual tax difference (USD): USD 312.50
Value basis Market valueCurrent value (USD) USD 200,000.00Supported target value (USD) USD 150,000.00Tax rate 1.25 Percent (%)Assessment ratio (%) 50%Unchanged fixed charges (USD/year) USD 100.00
Conditional on approval, the entered rate and unchanged fixed charges. A negative result is a tax increase, not savings.
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Reference
Cite This Calculator
APA & MLA▸
Use either format to cite this calculator in a paper, report, or resource list.
Compare supported values with explicit tax assumptions. This is an unofficial analysis, not an appeal filing. Conditional on approval, the entered rate and unchanged fixed charges. A negative result is a tax increase, not savings.
Value basis
▸
Market value is converted by the entered ratio. Assessed value is before exemptions; taxable value is after them.
Applied only to market-value inputs; enter the ratio from your notice. The 100% default is an editable assumption.
The same exemption is subtracted on both sides; taxable value has a zero floor. Already-taxable inputs are not reduced again.
Current and proposed annual tax in USD
▸
The entered rate applies to taxable value only. Select the unit explicitly.
Separate charges unrelated to assessed value remain unchanged.
Reconcile this difference with the bill. It may include charges or rules outside this simplified model.
Evidence completeness
▸
Completeness describes the worksheet, not admissibility, value, approval likelihood or a legal right to a reduction.
Use sale dates in YYYY-MM-DD format, property types and supported adjustments. No price-per-area size correction is inferred.
Enter assessment values for the same tax year (YYYY), property types and supported adjustments. Local assessment-equity rules still need review.
Repair cost is not automatically a value loss. Deduct only a supported market-value adjustment that is absent from your target.
Hypothetical cumulative differences
▸
Hypothetical totals assume the change continues under your chosen growth and cycle inputs. They do not forecast future bills or appeal outcomes.
Filing plus professional costs divided by a positive annual tax difference. This is financial break-even, not a likelihood of approval.
Unknown local procedure. Confirm your authority, tax year, valuation date, filing window, fee, form and evidence rules locally. This calculator cannot determine a deadline.
Labels, notes and filenames stay in this tab session and are excluded from saved state and shared links.
For education only; not tax, legal or filing advice. Confirm requirements with your local authority or a qualified adviser.
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Questions
Frequently Asked Questions
6 questions▸
Which rate unit should I use?+
The entered rate applies to taxable value only. Select the unit explicitly. Market value is converted by the entered ratio. Assessed value is before exemptions; taxable value is after them.
Which value basis should I select?+
Market value is converted by the entered ratio. Assessed value is before exemptions; taxable value is after them.
Does completeness predict a successful appeal?+
Completeness describes the worksheet, not admissibility, value, approval likelihood or a legal right to a reduction.
What does cost recovery mean?+
Filing plus professional costs divided by a positive annual tax difference. This is financial break-even, not a likelihood of approval.
Can this calculator determine my filing deadline?+
Unknown local procedure. Confirm your authority, tax year, valuation date, filing window, fee, form and evidence rules locally. This calculator cannot determine a deadline.
Are identifying notes included in saved or shared data?+
Labels, notes and filenames stay in this tab session and are excluded from saved state and shared links.
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Save & share
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