County Tax AtlasProperty tax by county & state

Independent reference using U.S. Census dataACS 2020–2024 5-year · 3,144 counties

Effective rate vs. mill rate: what the percentage means

Why a 1.2% effective rate and a posted millage are not the same number, and how to move between them.

Updated Oct 24, 2026

Two different questions

A mill rate (or nominal rate) is set by law and applied to taxable value. An effective rate is a result: tax paid as a share of market value. Exemptions, assessment ratios and valuation lag all sit between the two.

A county can have a high millage but a low assessment ratio, and end up with a modest effective rate — or the reverse.

How the figures here are built

Each effective rate on this site is median taxes paid ÷ median home value from the same American Community Survey release. It is a ratio of two separate medians, so it approximates the typical burden rather than describing any one household.

A rate shown as 1.00% is the same as about 10.0 mills on full market value, or roughly $10 per $1,000 of value.

When to be cautious

In areas with few owner-occupied homes the survey medians carry wide margins of error; we flag those records. Recent sharp changes in home prices can also pull the two medians apart for a year or two.

This guide is general information, not legal or tax advice. Rules differ by state, county and municipality — confirm specifics with your local assessor or a professional.

More guides

How property tax is calculated

The assessed value, assessment ratio and millage (mill rate) that turn a home value into an annual bill, and why two homes worth the same can be taxed differently.

Assessed value vs. market value

How assessors arrive at the number your tax is based on, how often it changes, and what caps and ratios do.

Homestead and other property-tax exemptions

Common exemptions that lower the taxable value of a primary home — homestead, senior, veteran and disability — and how they typically work.

How to appeal a property assessment

The usual steps, deadlines and evidence for challenging an assessed value you believe is too high.

Due dates, escrow and what happens if you fall behind

When property taxes are typically due, how mortgage escrow handles them, and the consequences of delinquency.

Property tax across the states: the big picture

Why effective property-tax rates vary so much from state to state, and what drives a high or low rate.

Ways to lower your property tax

Legitimate levers that reduce a property-tax bill: exemptions, an assessment appeal, and relief programs.