Methodology & Data Sources

Primary Data Source

Property tax, home value, and income data comes from the US Census Bureau's American Community Survey (ACS) 5-Year Estimates, covering the survey years 2020 through 2024. The ACS is the most comprehensive source of county-level property tax and housing data in the United States, used by researchers, policymakers, and real estate professionals nationwide.

County-level rent figures used in our rent-vs-buy comparisons come from HUD Fair Market Rents, published annually by the U.S. Department of Housing and Urban Development.

Rent-vs-own pages deliberately join the latest ACS property-tax vintage with the latest HUD FMR fiscal year. Those sources do not share a calendar: ACS lags the survey window, while FMR is a forward-looking fiscal publication. The join is a disclosed multi-source comparison (each year named on the page), not a same-population coverage ratio, and ACS-to-ACS year-over-year change metrics stay inside the tax tables only.

Census Tables Used

We pull the following ACS tables directly from the Census Bureau API:

• B25077: Median value of owner-occupied housing units, used for effective tax rate calculations
• B25103: Median real estate taxes paid, the primary property tax metric
• B19013: Median household income, used to calculate tax burden ratios
• B25091: Mortgage status by monthly housing costs, used for cost-burdened homeowner analysis

Derived Metrics

• Effective Tax Rate: Median real estate taxes paid ÷ median home value. This is an estimate of the effective rate, the actual amount paid relative to home value, not the nominal millage rate set by local governments.
• Tax Burden: Median real estate taxes ÷ median household income. Measures the share of income consumed by property taxes.
• County Rankings: Counties are ranked nationally on effective tax rate, median taxes paid, and tax burden. Rankings enable comparison across states that use different assessment practices.

Tax Affordability Score

Each county page can show a single letter grade and 0–100 composite that blends up to five ACS-derived dimensions into one comparable figure. Higher scores mean the county looks more affordable on those published medians relative to other U.S. counties. The score is comparative arithmetic for research and relocation context, it is not a recommendation to buy, sell, appeal, or move, and it is not anyone's personal tax bill.

Dimensions and base weights (missing inputs drop out and their weight redistributes so an incomplete county is not silently deflated):

• Rate relief (30%): effective tax rate, lower rates score higher
• Income room (25%): median tax ÷ median household income, lower shares score higher
• Bill size (20%): median annual tax, lower bills score higher (skipped when ACS top-codes the median at $10,000+)
• Mortgage premium (15%): mortgaged minus free-and-clear median tax, smaller gaps score higher
• Housing pressure (10%): median home value ÷ median income, lower ratios score higher

Each raw value is mapped to a 0–100 percentile score against fixed national breakpoints (approximate p10 / p25 / p50 / p75 / p90) measured on the 2024 ACS county file after excluding top-coded tax medians. For the 2024 release those breakpoints are: effective rate 0.44% / 0.57% / 0.80% / 1.16% / 1.52%; median bill $706 / $1,052 / $1,615 / $2,446 / $3,555; tax/income 1.32% / 1.78% / 2.46% / 3.37% / 4.43%; home-value/income 1.95× / 2.40× / 2.93× / 3.66× / 4.76×; mortgage gap −$5 / $127 / $300 / $557 / $929. Letter grades follow a standard A+–F scale on the weighted overall.

Coverage

PlainPropertyTax covers 3,152 counties and county-equivalents in all 50 states and the District of Columbia, plus the Census Bureau's own state-level ACS estimates (not a re-average of the county figures).

Processing Pipeline

We pull ACS 5-Year Estimate data tables directly from the Census Bureau API for all 3,152 counties and county-equivalents. Our ETL pipeline processes the data through several stages:

• Download ACS tables B25077, B25103, B19013, and B25091 for every county-level FIPS code in the United States
• Compute effective tax rates by dividing median real estate taxes paid (B25103) by median home values (B25077)
• Compute tax burden ratios by dividing median taxes by median household income (B19013)
• Build national and state-level rankings for all derived metrics, enabling cross-state comparison
• Pull the Census Bureau's own state-level ACS tables directly (not a re-average of county rows) for each state's headline figures, and separately compute the per-state range of its counties for context
• Precompute two cross-state county peer sets at build time: the four nearest effective rates in the latest release, and the four nearest median-tax changes against the release at least four years earlier. Same-state counties are excluded because each profile already has a separate in-state comparison block.

No data is fabricated or editorially modified. All base values come directly from the Census Bureau's published ACS estimates. Derived metrics (effective tax rates, burden ratios, rankings) use straightforward arithmetic documented on this page.

Update Schedule

The Census Bureau publishes new ACS 5-Year Estimates annually, typically in December. Each release reflects data collected over the preceding five calendar years. We commit to updating our database within 60 days of each annual ACS 5-Year release and each annual HUD Fair Market Rent publication (typically issued in the fall for the following fiscal year). The 5-year pooling method provides reliable estimates even for small counties but means the data represents a rolling average rather than a single point in time.

Our database currently holds the five most recent ACS 5-Year vintages (2020–2024 releases) for every county we track, and the two most recent HUD FMR publication years (FY 2025 and FY 2026). The next expected refresh is the ACS 2025 5-Year release (December 2026); year-over-year changes between releases are documented in our research reports.

Data Access

The full county-level property tax dataset is available as a property-tax.csv, covering every county we track with the same effective tax rate, median tax, and home value figures shown on each county page. This page declares that extract as a Dataset with a CSV DataDownload under a CC0 public domain dedication: free to reuse, adapt, or republish with no permission needed, though attribution to PlainPropertyTax as the compiling source is appreciated.

Limitations

• ACS figures are survey estimates with margins of error. Small counties with fewer respondents have larger uncertainties.
• ACS data reflects taxes actually paid by homeowners in the survey year, not the statutory tax rate set by local governments. Exemptions, assessment freezes, and assessment caps mean actual payments can differ significantly from applying the nominal rate to market value.
• Data is published with an approximate 12-18 month lag from the survey year. Rapid changes in home values or local tax rates may not be fully reflected.
• Effective tax rates are median-to-median ratios (median taxes / median home value), which may differ from rates computed for individual properties.
• Always verify property tax information with your local county assessor's office before making financial decisions.

Not Affiliated

PlainPropertyTax is not affiliated with the US Census Bureau, any county assessor's office, or any government agency. This site provides informational data only and does not constitute tax or financial advice.