What Is a Mill Rate?
A mill rate (also called millage) is the amount of property tax charged per $1,000 of a property's assessed value. One mill equals one-tenth of a cent, or $1 of tax for every $1,000 of assessed value. Local governments — counties, cities, and school districts — set mill rates each year to fund services such as schools, roads, fire, and police. This calculator works in any jurisdiction that uses the per-$1,000 millage convention; always confirm whether your area taxes the full assessed value or an assessed fraction of market value.
How to Use This Calculator
Enter your property's assessed value (the figure your local assessor places on the property, which may differ from market value) and the combined mill rate from your tax bill or assessor's website. The calculator returns your estimated annual property tax, the effective tax rate as a percentage of assessed value, and an estimated monthly amount for budgeting.
The Formula Explained
The core equation is $$\text{Tax} = \frac{\text{Assessed Value}}{1{,}000} \times \text{Mill Rate}$$. Dividing by 1,000 converts the value into "thousands," and each mill applies $1 of tax to each of those thousands. The effective rate is simply the tax divided by the assessed value, expressed as a percentage.
Worked Example
Suppose your home is assessed at $250,000 and your combined mill rate is 20 mills. $$\text{Tax} = 250{,}000 \div 1{,}000 \times 20 = 250 \times 20 = \mathbf{\$5{,}000 \text{ per year}}$$ The effective rate is \(5{,}000 \div 250{,}000 \times 100 = 2.0\%\), and the monthly estimate is \(5{,}000 \div 12 \approx \$416.67\).
FAQ
Is the mill rate the same as the tax rate? They describe the same thing differently. A mill rate of 20 equals a tax rate of 2.0% of assessed value (\(20 \div 1{,}000 \times 100\)).
What if my area uses an assessment ratio? Some places tax only a fraction of market value. First multiply market value by the assessment ratio to get assessed value, then enter that number here.
Why is my actual bill different? Exemptions (homestead, senior, veteran), special assessments, and rounding can change the final figure. This tool gives a close estimate before deductions.
