Property taxes vary more than almost any other homeownership cost — not just state to state, but county to county and sometimes street to street depending on local school districts and municipal service areas. Understanding how the calculation actually works helps you estimate costs accurately before you buy.
The Basic Formula
Assessed Value vs. Market Value
Assessed value is not always the same as what you paid for the home. Many jurisdictions assess at a percentage of market value (sometimes 80–100%, sometimes lower), and assessments are often updated on a fixed cycle — annually in some areas, every few years in others — rather than continuously tracking the market in real time.
Why Rates Vary So Much
Property tax rates fund local services — schools, police and fire, roads, parks — and reflect the specific budget needs of each taxing authority overlapping your property (which can include county, city, school district, and special districts all at once). This is why two similarly priced homes in neighboring towns can have meaningfully different tax bills.
Key insight: Never assume the seller's current tax bill will carry over unchanged. Many jurisdictions reassess property at or near its new sale price after a transfer, which can increase the tax bill significantly compared to what the previous owner was paying — especially if they'd owned the home for many years under an older assessment.
Appealing an Assessment
If you believe your property is over-assessed relative to comparable homes, most jurisdictions allow a formal appeal process, typically requiring comparable sales evidence and submission within a specific window after the assessment notice. Success rates and processes vary significantly by location — check your local assessor's office for specific procedures and deadlines.
Exemptions to Check For
Many areas offer property tax exemptions or reductions for primary residences (homestead exemptions), seniors, veterans, or disabled homeowners. These can meaningfully reduce your effective tax bill and are worth researching for your specific location and eligibility.