How is Montana property tax calculated?

Montana multiplies your property's market value by a class tax rate (about 1.35% for residential property) to get the taxable value, then multiplies that taxable value by your local total mill levy. One mill equals one-thousandth of taxable value.

A mill is one dollar of tax per 1,000 dollars of taxable value. Counties, cities, schools and districts each set mills, and the combined total — often 500 to 750 mills in Montana — is applied to your taxable value to produce the bill.

What is Montana's residential tax rate?

The residential class tax rate is roughly 1.35% of market value. So a 400,000 dollar home has a taxable value of about 5,400 dollars before the mill levy is applied.

Is there property tax relief in Montana?

Yes. The Property Tax Assistance Program (PTAP) and other relief programs can reduce taxable value for qualifying low-income, elderly or disabled homeowners. This tool lets you apply an optional percentage reduction to model that relief.

How accurate is this estimate?

It is a close estimate. Actual bills depend on your county's exact mill levy, special districts, and any exemptions, so always confirm against your official Montana property tax statement.

Montana Property Tax Estimator

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Montana property tax can look confusing because the bill is not a simple percentage of your home’s value. Instead the state applies a low class tax rate to your market value to get a small “taxable value”, then multiplies that by your local mill levy. This estimator walks through both steps so you can see what your annual bill is likely to be.

How it works

The estimate follows Montana’s official two-step method:

Taxable value. Your property’s market value (set by the Montana Department of Revenue) is multiplied by the residential class tax rate of about 1.35%. A $400,000 home therefore has a taxable value of roughly $5,400.
Optional relief. If you qualify for the Property Tax Assistance Program or a similar reduction, an optional percentage is subtracted from the taxable value.
Apply the mill levy. The taxable value is multiplied by your total mill levy. A mill is $1 of tax per $1,000 of taxable value, so the formula is taxable_value × mills ÷ 1000. Montana levies commonly total 500–750 mills.

Tips and example

A $400,000 home with a 1.35% tax rate has a taxable value of $5,400. In a county with a 600-mill levy, the estimated annual tax is 5,400 × 600 ÷ 1000 = $3,240.

Your real mill levy is printed on your property tax statement — entering it gives the most accurate result. Mill levies vary widely between counties and even between districts within a county, so the dropdown values here are representative starting points, not exact figures for your parcel.