How Property Taxes Are Calculated Topical Map: SEO Clusters

Multiply your property's assessed value by the local assessment ratio (if applicable) to get the taxable value, then multiply the taxable value by the combined millage or tax rate (expressed as a decimal) and divide by 1 if rate is decimal or by 1,000 if using mills. Example: $250,000 assessed value × 80% assessment ratio = $200,000 taxable value; $200,000 × 0.025 (2.5% tax rate) = $5,000 annual tax.

Market value is what a buyer would pay on the open market; assessed value is the value the assessor assigns for tax purposes and may be a percentage of market value (the assessment ratio) or equal to market value depending on the jurisdiction. Local tax bills are based on the assessed (or taxable) value after exemptions and ratios, not raw market price.

A mill is one-thousandth of a dollar ($1 per $1,000 of taxable value). To compute taxes with mills, multiply taxable value by the number of mills and then divide by 1,000; e.g., 25 mills on $200,000 taxable value = (25 × 200,000) / 1,000 = $5,000.

Exemptions reduce the taxable value before the tax rate is applied; some are flat-dollar reductions (subtract $X) and others are percentage or full reductions for eligible owners. Apply exemptions to assessed value first—if you have a $50,000 homestead exemption on a $300,000 assessed value, taxable value becomes $250,000 and your tax is calculated on that lower amount.

Reassessment frequency varies by state and county—some reappraise annually, others every 2–5 years or on a longer schedule; frequency affects how quickly market changes show up in your assessed value. If your area has annual reappraisals, market appreciation or declines will be reflected faster, increasing or decreasing tax liability sooner.

Comparable recent sales of similar properties, documented errors in the assessor’s property characteristics (square footage, number of bathrooms, lot size), and professional appraisal reports are strongest evidence. Successful appeals commonly reduce assessed value by roughly 5–20% depending on the error or market timing—results vary widely by jurisdiction and case quality.

Your total tax rate is the sum of all overlapping taxing authorities (municipal, county, school district, special districts). Counties or municipal treasurers post a combined rate or millage table on their website and your tax bill will list the constituent rates; contact the tax collector or assessor’s office if the combined rate is not published.

Commercial properties are typically assessed on fair market value and may use income capitalization or cost approaches for valuation; agricultural parcels often qualify for use-value assessment that taxes based on agricultural productivity rather than market value. These different methodologies change taxable value calculations and can produce materially different effective tax rates.

Most jurisdictions add value from permitted improvements at the next reassessment or when a construction completion report is filed; permitted additions, finished basements, or new structures usually increase assessed value immediately or at the next scheduled reappraisal. Unpermitted work may remain off the assessor’s record until discovered, but correctly permitted work should be reflected in your tax bill scheduling information from the assessor’s office.

Escrowing for taxes is a payment mechanism only; it does not change how taxes are calculated or the statutory billing deadlines and penalties. You still must monitor assessment notices and appeal deadlines because missed appeals cannot be cured by your mortgage servicer’s escrow arrangements.