One dollar of tax per thousand dollars of assessed value. Twenty mills is two percent of assessed value, which is not the same as two percent of market value unless the assessment ratio is 100%.

Why is my assessed value below what I paid?

Because many states assess at a fraction of market value. A low assessment ratio with a high mill rate can produce the same bill as the opposite, which is why neither number means much alone.

TaxpropertyUnited States only

Property Tax Calculator

US property tax from the mill rate. A mill is one dollar per thousand of assessed value, and the assessment ratio means assessed value is often well below market value.

Also called: mill rate calculator, property tax estimate.

Annual property tax

$8,000.00

$8,000.00 a year, or $666.67 a month in escrow. That is 2% of market value, on an assessed value of $400,000.00 after 0 of exemptions.

Assessed value

$400,000.00

Taxable value after exemptions

$400,000.00

Monthly escrow

$666.67

Effective rate on market value

Tax per 1,000 of assessed value

$20.00

How this is calculated

Computed from the published rates for the tax year you selected, which is not necessarily the current year. A calculation, not tax advice, and it does not know anything about your circumstances beyond the figures entered.

Method and background

This is what the calculation gives for the numbers you entered. It is an estimate, not advice, and it knows nothing about your situation beyond those numbers. Rules for United States change on a published schedule; the effective date is shown on every rule-based tool.

How this is calculated

Three numbers do the work. The assessment ratio converts market value to assessed value and varies enormously by state, from full market value down to a small fraction. Exemptions such as a homestead exemption come off the assessed value. The mill rate then applies, where one mill is one dollar per thousand, so a rate of twenty mills is two percent of assessed value. Comparing mill rates between jurisdictions is meaningless without also comparing assessment ratios.

tax = (market value * assessment ratio, less exemptions) * mill rate / 1000

V: Market value (currency)
a: Assessment ratio (decimal)
m: Mill rate (mills)
E: Exemptions (currency)

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

twenty mills at full assessment

Market value: $400,000.00
Assessment ratio: 100%
Mill rate: 20
Homestead and other exemptions: $0.00

Annual property tax$8,000.00

400,000 * 20 / 1000, worked by hand

Open this example

a low assessment ratio halves the bill

Market value: $400,000.00
Assessment ratio: 50%
Mill rate: 20
Homestead and other exemptions: $0.00

Annual property tax$4,000.00

boundary: why mill rates alone mean nothing

Open this example

a zero mill rate is no tax

Market value: $400,000.00
Assessment ratio: 100%
Mill rate: 0
Homestead and other exemptions: $0.00

Annual property tax$0.00

degenerate case

Open this example

Method and limits

What it assumes

One combined mill rate covering county, city and school district.

What it deliberately does not model

Special assessments and district levies are often billed separately.
Caps on annual assessment increases exist in several states and are not modelled.

Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator

Frequently asked questions

What is a mill?: One dollar of tax per thousand dollars of assessed value. Twenty mills is two percent of assessed value, which is not the same as two percent of market value unless the assessment ratio is 100%.
Why is my assessed value below what I paid?: Because many states assess at a fraction of market value. A low assessment ratio with a high mill rate can produce the same bill as the opposite, which is why neither number means much alone.