Home / How it works
How a property tax bill is put together
The posted millage rate on a tax bill and the effective rate you see in Census data are related, but they are not the same number.
From market value to a bill
Most jurisdictions start with an estimate of market value. Some tax the full value (Texas and, after reappraisal, North Carolina). Georgia taxes 40% of fair market value. New Jersey municipalities assess at a local percentage of true value. Exemptions then reduce taxable value (a Texas school homestead, a Georgia $2,000 homestead, a North Carolina elderly exclusion) or reduce the bill itself (a New Jersey veteran deduction). Remaining taxable value is multiplied by each taxing unit's rate and added up. Rates may be shown as mills ($1 per $1,000) or dollars per $100 of value.
Why effective rates are lower than raw millage
A county that levies 20 mills is charging $20 per $1,000 of taxable value, which would be 2% if every home were taxed on full market value with no exemptions. Homestead exemptions, assessment caps and preferential farm or historic programs pull the typical tax paid well below that. The American Community Survey asks homeowners what they paid and what their home is worth. Dividing those two medians produces an effective rate you can compare across counties and states.
How the calculators on this site differ
- The county effective-rate estimate multiplies your value by median taxes ÷ median value. It already embeds typical exemptions, so you should not also subtract a homestead from it.
- The detailed state calculators apply published exemption rules to a millage or per-$100 rate that you type from your bill. Those rates are placeholders until you replace them.
- Florida's detailed millage and Amendment 3 tools remain on Florida Tax Atlas.
See methodology for sources and the rules we encoded.
Sources
- Tax Foundation, Property Taxes by State and County, 2026 (published March 16, 2026; county median housing value, median real estate taxes paid, and statewide rankings from the US Census Bureau American Community Survey 2024 5-year estimates)
- US Census Bureau, American Community Survey 2024 5-year estimates (tables for median housing value and median real estate taxes paid; Florida county figures match the extract used on Florida Tax Atlas, ACS release dated December 2025 in that project configuration)
- Florida Tax Atlas (county millage, homestead and Amendment 3 calculators; Amendment 3 approved November 3, 2026)
Common questions
What is a mill?
One mill is $1 of tax per $1,000 of taxable value. Twenty mills equal a 2% tax on taxable value, before exemptions change the base.