Tax Assessment vs Market Value: Property Tax Guide 2026

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Property Tax · Market Value · Assessed Value · Taxable Value · Appeals

One Property Can Have Three Different Values—and All Can Be Correct

Market value estimates what a property would sell for under normal market conditions. Assessed value is the value placed on the property under local tax-assessment rules. Taxable value is often what remains after assessment limits, exemptions or other statutory adjustments.

The mistake is assuming one formula works nationwide. Some jurisdictions assess at 100% of market value, some use a fixed assessment ratio, and others cap or limit assessed value based on ownership history. This guide shows how to identify the number on your record, calculate what actually drives the bill and decide whether a value appeal, exemption correction or tax-rate question is the right next step.

See the difference Calculate the tax path Check appeal reason
Most important rule: never compare your home’s assessed value with its sale price until you know the local assessment system. A $175,000 assessment can represent a $500,000 market value in a 35% assessment-ratio jurisdiction, while in another jurisdiction an assessed value near $500,000 may be normal.

Quick answer: market value and assessed value answer different questions

Market value asks, “What would this property likely sell for under normal market conditions?” Assessed value asks, “What value does the tax system place on this property under the jurisdiction’s assessment rules?” Taxable value asks, “What value remains after applicable limits, exemptions or reductions for this taxing unit?”

1 Find market value Look for fair market, just, full, true or appraised market value.
2 Find assessment rule Identify ratio, base-year system, cap or appraisal limitation.
3 Find taxable value Check exemptions and taxing-unit-specific reductions.
4 Find the rate Apply the correct millage, levy or percentage to the correct tax base.

Ten facts that prevent the most common mistakes

Market value Probable open-market sale value
Assessed value Tax-system value under local rules
Taxable value Often assessed value after exemptions
Assessment ratio Assessed ÷ market value
Ratio nationwide Not universal
Tax rate Separate from property value
Sale price Evidence—not automatically every jurisdiction’s assessment
Exemptions Can reduce taxable value
Assessment caps Can create large market/assessed gaps
Appeal target Usually value/data—not elected tax rate

Choose the question your property record is creating

Value decoder

Do not stop at “assessed value vs. market value”—there are usually more numbers

Five property values you may encounter
Value
What it means
Who mainly uses it
What it is best for
Market Value
Estimated price in a normal arm’s-length transaction as of a specific date.
Assessors, appraisers, buyers, sellers and lenders.
Understanding current economic value.
Appraised Value
A value conclusion produced by an appraisal process. In some tax systems this label is close to market value; in others it has a statutory meaning.
Appraisal districts, assessors or licensed appraisers.
Depends on the jurisdiction and appraisal purpose.
Assessed Value
Value entered under the property-tax assessment system after applying applicable assessment-level rules.
Local assessing authority.
Understanding the tax assessment base.
Taxable Value
Value to which a taxing unit’s tax rate is ultimately applied after applicable exemptions or reductions.
Taxing and collection systems.
Estimating the actual property-tax charge.
Sale Price
Actual amount paid in a specific transaction.
Buyer, seller, assessor, appraiser and lender.
Strong market evidence when the sale was recent and arm’s length.
Online Home Estimate
Automated valuation estimate produced by a private model.
Consumers and real-estate platforms.
A rough reference—not tax assessment proof by itself.

Different does not automatically mean wrong

The International Association of Assessing Officers defines an assessment level as the relationship between assessed value and market value. That relationship can be 100%, a statutory fraction, or the result of an acquisition-value or capped system.

The useful question is therefore not “Why don’t these numbers match?” but “What local rule explains the relationship between these numbers?”

Property-tax calculation

The tax bill is a chain—not one percentage of your home’s price

MARKET VALUE Economic estimate ASSESSMENT Ratio / cap / base RELIEF Exemptions / limits TAXABLE VALUE Tax base TAX BILL Rate + charges

Illustration only: a fractional-assessment jurisdiction

$500K Illustrative market value
35% Illustrative assessment ratio
$175K Illustrative assessed value
$25K Illustrative exemption
$150K Illustrative taxable value
Example math: $500,000 market value × 35% assessment ratio = $175,000 assessed value. If a $25,000 exemption applies, taxable value becomes $150,000. At a hypothetical 2% effective tax rate, the base tax would be $3,000 before special assessments or other charges.
Do not copy this 35% example into your own tax calculation unless your jurisdiction actually uses 35%. Ohio uses 35% for real-property assessed value, but Texas generally starts from market value, Florida uses assessment limits before exemptions, California uses an acquisition-value framework, and New York municipalities can operate at differing assessment levels.
Millage conversion: 1 mill equals $1 of tax per $1,000 of taxable or assessed value to which the mill applies. A 20-mill rate is mathematically 2%, but exemptions and different taxing-unit bases can make the actual bill more complicated.
Assessment-ratio test

Use this equation before assuming the assessment is too high

Property-specific ratio

Assessed Value ÷ Market Value = Assessment Ratio.

Example: $175,000 ÷ $500,000 = 35%.

≠
Effective tax rate

Property Tax ÷ Market Value = Effective Tax Rate.

This is a different measurement and should not be confused with the assessment ratio.

100% level
100%
75% level
75%
55% level
55%
35% level
35%
20% level
20%
Why a ratio can mislead: if the “market value” you are using comes from an online home estimate rather than the assessor’s valuation date, the ratio may compare two values from different dates and different valuation methods.
State-by-state differences

The same $500,000 house can produce very different assessed values

Examples of how assessment systems differ
Jurisdiction example
How market and assessed value relate
Why the gap can exist
Important owner lesson
Ohio
Real property is assessed at 35% of appraised fair market value for tax calculations.
State assessment ratio.
A $175,000 assessed value can correspond to a $500,000 appraised market value.
Texas
Taxable property is generally appraised at market value, but appraisal limitations and exemptions can produce lower appraised/taxable values.
Homestead cap, non-homestead circuit breaker, exemptions or special appraisal.
Do not look for a universal 35% or 80% Texas assessment ratio.
California
Proposition 13 generally uses acquisition-based assessed value with annual inflation increases limited to no more than 2%, absent reassessable events.
Ownership date and new construction can determine base-year value.
Two similar neighboring homes can have very different assessed values.
Florida
Just/market value minus assessment differentials equals assessed value; assessed value minus exemptions produces taxable value.
Save Our Homes and other caps can create an assessment differential.
School and non-school taxable values can differ because exemptions do not always apply identically.
New York
Municipalities can assess at 100% or a fractional level of market value; equalization rates measure the overall assessment level.
Local assessment levels and reassessment timing differ.
Convert the assessment to estimated market value before comparing communities.
Cook County, Illinois
Residential property is assessed at 10% of fair market value while most commercial property uses a 25% assessment level before equalization.
Property classification plus state equalization.
Property class matters before comparing assessed values.
Find your county property office Read the Texas property-search guide
How market value is estimated

Your assessor usually values thousands of properties—not just your house

Local assessors commonly use mass-appraisal systems. The underlying valuation techniques still resemble the three traditional approaches to value: sales comparison, cost and income.

Sales comparison

Compares the subject property with relevant recent sales, adjusting for differences such as location, size, quality, condition, age, lot and features.

Common for homes and vacant land
Cost approach

Estimates what it would cost to replace or reproduce improvements, subtracts depreciation and adds land value.

Useful for newer or special-use improvements
Income approach

Analyzes the income-producing capacity of property using rents, operating expenses, vacancy and capitalization assumptions.

Common for income-producing property

Why a mass appraisal can differ from a private appraisal

Mass appraisal

Values many properties using standardized models, common data and statistical testing.

Private appraisal

Usually analyzes one property for a particular assignment, date and purpose.

Sale price

Represents one transaction and may be strong evidence when recent, arm’s length and relevant to the valuation date.

Best appeal insight: a good value challenge does not merely say “Zillow is lower” or “my taxes are too high.” It identifies a factual error, unsuitable comparable, condition issue, relevant arm’s-length sale, unequal treatment or another legally recognized valuation problem.
Why the values do not match

A large gap can be normal—or it can expose a problem

Statutory assessment ratio A jurisdiction deliberately assesses at a percentage of market value.
Assessment cap Annual assessed-value growth can be limited while market value continues rising.
Acquisition-value system Ownership history can control the assessment base until a reassessable event occurs.
Assessment cycle lag The tax roll may reflect an earlier valuation date or reassessment cycle.
Market moved quickly Sale prices can change faster than an annual or periodic assessment roll.
Homestead or other limit Legal protections can reduce assessed or taxable growth without reducing market value.
Special valuation Agricultural, conservation or other qualifying property may use a non-market valuation method.
Exemptions Exemptions can reduce taxable value even when assessed or market value stays unchanged.
Property data error Wrong square footage, building class, condition or land data can distort an assessment.
Market decline Assessed value can temporarily look high if market conditions fell after the assessment date or between reassessments.
Sanity check: compare values using the same valuation date. A January 1 tax value should not automatically be judged against a private estimate generated many months later in a sharply changing market.
Buyer and seller intent

Do not use the seller’s current property tax bill as your future bill

This is one of the most expensive misunderstandings for buyers. The seller may have an old base-year value, homestead cap, senior relief, agricultural classification, disabled-veteran exemption or other treatment that will not continue for the buyer in the same way.
Which value matters for each real-estate decision?
Decision
Value that matters most
Do not rely on
Setting listing price
Current market evidence and relevant comparables
Tax assessed value alone
Making an offer
Current market value, condition and comps
Assuming assessed value is the seller’s minimum value
Mortgage underwriting
Lender’s appraisal and loan requirements
County tax value as a substitute for lender appraisal
Estimating future property tax
Likely post-purchase tax base, buyer exemptions and current tax rates
Seller’s current net bill alone
Appealing tax value
Assessor’s valuation date, property facts and accepted evidence
Current list price alone

Before buying, ask these five tax questions

01
MARKET VALUE What value does the assessor currently place on the property?
02
ASSESSED VALUE Is a ratio, cap or base-year system reducing it?
03
EXEMPTIONS Which seller exemptions disappear or require a new buyer application?
04
REASSESSMENT Does a sale trigger reassessment or a new taxable base?
05
TAX RATE Which county, city, school and special-district rates apply?
Why did my tax bill increase?

A higher bill does not always mean the assessor raised market value

Diagnose the increase before filing the wrong appeal
What changed?
Likely cause
Best place to investigate
Market value increased
New market evidence, revaluation or updated property characteristics.
Assessor / appraisal office
Market value same, assessed value increased
Cap catch-up, base-year factoring or assessment-ratio application.
Assessment calculation and cap rules
Assessed value same, taxable value increased
Exemption expired, reduced or no longer applies.
Exemption record
Taxable value same, bill increased
Tax rate, levy or special assessment changed.
Taxing unit / tax collector
Bill jumped after purchase
Reassessment, loss of seller’s cap/exemptions or new ownership base.
Assessor + local post-sale tax rules
One taxing unit increased more than another
Different exemptions or rates by taxing unit.
Unit-specific taxable value and tax rate
Do not protest a tax rate through a value appeal. A valuation appeal generally addresses the property’s value, assessment classification, exemption or other assessable issue. Tax rates and levies are commonly adopted through a different local-government process.
Appeal decision tree

Appeal the component that is actually wrong

V
VALUE Market estimate
Comparable sales
Condition
Appraisal
D
DATA Square feet
Buildings
Land
Classification
E
EXEMPTION Homestead
Senior
Veteran
Disability
C
CAP / RATIO Assessment level
Limit
Base-year
Equalization
$
TAX RATE Levy
Millage
Budget
Special charge
Market value looks too high Compare relevant arm’s-length sales near the jurisdiction’s valuation date.
Square footage is wrong Correct the property characteristics before arguing over comparable sales.
Assessed value exceeds the permitted ratio Verify the jurisdiction’s statutory assessment level and whether an equalization factor applies.
Expected homestead is missing This may be an exemption filing/correction issue rather than a market-value appeal.
Cap disappeared after sale Check whether ownership change reset the protected assessment base.
Tax rate increased Review the taxing unit’s rate-adoption, levy or budget process rather than only challenging assessed value.
Special assessment appeared Identify the issuing jurisdiction and project before assuming it is ordinary ad valorem tax.
Neighbor pays less Compare assessment history, ownership date, exemptions, property class and taxing units before alleging unequal treatment.
Deadlines are local. Do not rely on a nationwide “30-day” appeal rule. Some jurisdictions use fixed calendar dates, others count days from notice mailing, and some have separate informal review, board appeal and court deadlines.
Assessor call script “I am reviewing parcel [parcel/account number] for tax year [year]. The record shows market value [amount], assessed value [amount] and taxable value [amount]. Can you confirm the local assessment level or cap, valuation date, exemptions applied and the deadline/form for correcting or appealing this specific issue?”
Evidence that actually matters

Build the appeal around the reason—not around frustration with the bill

Recent arm’s-length sale Purchase contract, closing statement and sale facts close to the valuation date.
Comparable sales Similar location, use, size, age, quality, condition and date.
Incorrect characteristics Measurements, floor plans, permits or photographs showing the assessor’s data is wrong.
Physical condition Inspection reports, dated photos and repair estimates documenting value-impacting defects.
Income evidence Actual rents, vacancy, operating expenses and market-derived capitalization evidence where income approach is relevant.
Unequal assessment Comparable assessment records analyzed under the jurisdiction’s permitted equity standard.

Weak evidence that often needs more support

Online home estimate with no valuation-date analysis
Listing price rather than closed sale evidence
Neighbor’s tax bill without exemption history
Repair complaint without photos or estimates
Sale from a very different neighborhood
Foreclosure or non-arm’s-length transfer treated as a normal comparable
Current market data from months after the official valuation date
“My tax is too high” without identifying the assessment component believed to be wrong
Office routing

Value, payment and deed questions often belong to different offices

Find the office that can actually solve the problem
What you need
Typical office title
What that office usually controls
Market / assessed value
Assessor, Property Appraiser, Appraisal District, PVA or property-focused Auditor
Assessment roll, valuation, property characteristics and many exemptions.
Tax bill / payment
Treasurer, Tax Collector, Trustee, Sheriff tax office or Tax Assessor-Collector
Current balance, payment, receipt and delinquency.
Deed / lien / mortgage
Recorder, Register of Deeds, County Clerk or Clerk of Court
Recorded real-property instruments.
Formal value challenge
Board of Review, Assessment Appeals Board, ARB or equivalent
Formal administrative assessment appeal.
Tax rate / levy
City, county, school district or other taxing unit
Budget, levy and rate adoption subject to local law.
Find the correct county office See Texas office routing
Property-value glossary

Decode the terms printed on tax records and assessment notices

Assessment terminology in plain English
Term
Meaning
Common confusion
Market Value
Most probable sale price under normal open-market conditions as of a specified date.
Not necessarily the property’s assessed or taxable value.
Assessed Value
Value entered under the jurisdiction’s property-tax assessment rules.
May be market value, a fraction of it or a legally limited value.
Taxable Value
Value remaining after applicable exemptions or other adjustments for a taxing unit.
Different taxing units can have different taxable values for the same property.
Assessment Ratio
Assessed value divided by market value.
Not the property-tax rate.
Equalization Rate
A measure used in some systems to relate aggregate assessed value to full market value.
Often used for cross-jurisdiction uniformity rather than as a simple owner discount.
Mill
$1 of tax per $1,000 of the applicable taxable or assessed value.
50 mills equals 5%, not 50%.
Homestead Exemption
Property-tax relief for a qualifying principal residence under applicable law.
Usually does not change the property’s economic market value.
Assessment Cap
A legal limitation on how quickly an assessment or appraised value can increase.
Can limit taxable growth without limiting market-value growth.
Special Assessment
Charge imposed for a specific improvement or service under local law.
Not necessarily part of the ordinary ad valorem tax rate.
Mass Appraisal
Valuation of many properties using standardized methods, common data and statistical testing.
Different from a lender’s individual property appraisal.
10 practical answers

Tax assessment vs. market value FAQs

What is the difference between tax assessed value and market value?

Market value estimates what a property would likely sell for under normal market conditions as of a specific date. Assessed value is the value placed on the property under the local property-tax assessment system. Depending on the jurisdiction, assessed value may equal market value, represent a percentage of it or be limited by a cap or base-year rule.

Is assessed value always lower than market value?

No. It is often lower in fractional-assessment, capped or acquisition-value systems, but there is no nationwide rule requiring assessed value to be lower. Reassessment timing, market declines and local assessment levels can also affect the relationship.

How do I calculate assessed value from market value?

If your jurisdiction uses a fixed assessment ratio, multiply market value by that ratio. For example, $500,000 multiplied by 35% equals $175,000. Do not use that formula until you verify that your jurisdiction actually uses a 35% ratio.

What is taxable value?

Taxable value is generally the value to which a taxing unit applies its tax rate after applicable exemptions, assessment limitations or other statutory adjustments. The exact calculation and terminology differ by state.

Why is my home’s assessed value much lower than its sale price?

The difference may result from a statutory assessment ratio, homestead cap, acquisition-value system, reassessment lag, special valuation or another local tax rule. A large gap is not automatically an assessment error.

Will my property taxes automatically increase to the purchase price after I buy a house?

Not everywhere. Some jurisdictions reassess after a change in ownership, while others use annual market appraisal or different rules. A buyer can also lose seller-specific exemptions or caps. Check the local post-sale assessment rules instead of assuming the seller’s bill will continue.

Why did my tax bill rise when market value stayed the same?

The assessed value may have caught up under a cap, an exemption may have changed, the tax rate may have increased or a special assessment may have been added. Compare market value, assessed value, taxable value, exemptions and tax rates separately.

Should I use assessed value to decide what a home is worth?

Usually not by itself. Buyers, sellers and lenders generally rely more heavily on current market evidence and property-specific appraisal information. Tax assessed value is designed for taxation and may reflect ratios, caps or older base values.

Can I appeal if assessed value is higher than market value?

Potentially. First verify the jurisdiction’s assessment level, valuation date and equalization rules. Then compare the assessor’s market-value conclusion with relevant evidence. Appeal procedures and deadlines are local, so use the official assessor or appeal-board instructions.

What evidence is strongest for a property tax appeal?

Useful evidence can include a recent arm’s-length sale near the valuation date, well-matched comparable sales, documented property-data errors, condition evidence, repair estimates, appropriate income information and other evidence accepted by the local appeal process.

Information reviewed August 22, 2026: assessment terminology and assessment-level concepts were checked against IAAO and current assessor guidance. State examples were verified against current official materials from Ohio county auditors, the Texas Comptroller, California State Board of Equalization, Florida Department of Revenue and New York State Department of Taxation and Finance. The purpose of the state examples is to demonstrate why no single assessed-value formula works nationwide.
Independent Guide — Important Tax and Valuation Disclaimer: CountyAuditors.org is an independent informational directory and is not a county assessor, property appraiser, appraisal district, treasurer, tax collector, recorder, board of review or taxing authority. Assessment ratios, valuation dates, exemptions, caps, equalization rules, appeal deadlines and tax rates differ by state and locality. Examples on this page explain concepts and are not a substitute for the live property record or current local law. Confirm your property’s values, tax base, appeal rights and filing deadlines with the responsible official office before filing, paying or making a real-estate decision.
Ohio Auditor Tools · Tax Year 2026

10 Ohio Property Tax Calculators & Auditor Tools

Built specifically for Ohio's 35% assessment ratio, current DTE forms, and 2026 Homestead, Owner-Occupancy, CAUV, Conveyance Fee, and Board of Revision rules. Every number reflects verified Ohio Department of Taxation amounts.

Homestead: $29,000 Enhanced Vet: $58,000 OAGI limit: $41,000 Assessment: 35% of market BOR filing: Free · DTE 1

Annual Tax Bill Estimator

OHIO

Applies Ohio's 35% assessment ratio plus your county's effective millage tier — the actual math your auditor uses.

Pick a county tier and enter your market value.

Homestead Reduction Calculator

DTE 105A

2026 Ohio Homestead: $29,000 general or $58,000 enhanced (100% disabled vet, KIA spouse). OAGI under $41,000 required for non-veteran applicants.

Pick your situation and enter your home value.

Owner-Occupancy & Non-Business Credits

DTE 105C

Every Ohio owner-occupied home qualifies for the 2.5% Owner-Occupancy Credit plus the automatic 10% Non-Business Credit. Most owners don't realize these stack.

Enter your annual tax to see both credit amounts.

Conveyance Fee Calculator

ORC 322

When you sell or transfer Ohio property, the auditor collects $1 state + up to $3 county per $1,000, plus $0.50 per parcel. Counties choose their rate.

Enter sale price and pick your county rate.

CAUV Agricultural Savings

DTE 109

Ohio's Current Agricultural Use Value cuts taxable value dramatically for farmland (10+ acres, or smaller with $2,500+ annual gross income).

Enter both market and CAUV values to see savings.

Mill Rate Converter

Ohio tax rates appear three ways on auditor sites: mills, percent, or dollars per $1,000. Convert between them instantly.

Enter a rate to see all three forms.

Parcel Number Cleaner

Ohio's 88 counties each format parcels differently — Franklin uses 010-123456-00, Cuyahoga uses 001-23-456, Hamilton uses 100-0001-0001-00. Auto-detects.

Paste any Ohio county parcel to format it.

35% Ratio Sanity Check

Ohio law sets taxable value at 35% of market value. If yours is significantly higher, you're a strong BOR appeal candidate.

Enter both values to compare against Ohio's 35% target.

BOR Appeal Savings

DTE 1

A successful Board of Revision complaint typically cuts your value 10–20%. Filing is free and stays in effect until the next reappraisal.

Enter your tax bill and reduction estimate.

BOR Deadline Countdown

MAR 31

Ohio's statutory Board of Revision filing deadline is March 31 for the prior tax year. Miss it and you wait until next year — no extensions.

Set your deadline to start the countdown.

Verify with the official Ohio source

These calculators use the verified 2026 Ohio Department of Taxation amounts and statutory rules. For your exact bill, exemption status, and county-specific deadlines, always confirm with your county auditor and the Ohio Revised Code:

Ohio Dept. of Taxation — Real Property DTE Forms (105A, 105C, 1, 109) ORC 5715 — Board of Revision ORC 5713 — Taxable Real Property ORC 322.02 — Conveyance Fee ORC 319.54(F)(3) — State Fee ORC 5713.30 — CAUV tax.ohio.gov — Main Portal

Estimates use Ohio's 35% statutory assessment ratio and effective tax rate tiers averaged across major Ohio counties. Your actual bill depends on local school levies, voted millage, inside vs. outside millage splits, House Bill 920 reduction factors (HB 920), and special assessments. The 2026 Homestead general amount ($29,000) and enhanced amount ($58,000) reflect HB 187 inflation indexing — your county auditor's office may show slightly different transitional figures. Nothing here is legal or tax advice. CountyAuditors.org is an independent informational directory, not affiliated with any county government.

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