Land records · Parcel maps · October 6, 2026
What Is a Mill Rate? How Property Tax Is Figured
What is a mill rate? A property tax rate in dollars per $1,000 of assessed value. How to use mills to estimate a tax bill, with a worked example.
What is a mill rate? A mill rate, also called a millage rate, is a way of expressing a property tax rate. One mill equals one dollar of tax for every $1,000 of assessed value, or one-tenth of a cent per dollar. To estimate a tax bill, multiply the taxable assessed value by the mill rate and divide by 1,000. A home with a taxable assessed value of $200,000 in a 25-mill district would owe about $5,000 a year. This page is general land-records background, not legal advice.
The formula
Tax = taxable assessed value x mill rate / 1,000
| Assessed value | Mill rate | Annual tax |
|---|---|---|
| $150,000 | 20 mills | $3,000 |
| $200,000 | 25 mills | $5,000 |
| $300,000 | 32.5 mills | $9,750 |
Assessed value is not always market value
Many states assess property at a fraction of market value. For example, some use 70 percent, others 10 to 40 percent depending on property class. A home worth $300,000 at a 70 percent assessment ratio has an assessed value of $210,000. The mill rate applies to the assessed value after any exemptions. See how is property tax calculated.
Adding up the levies
The total mill rate on a tax bill is usually the sum of several taxing districts:
- County.
- City or town.
- School district.
- Fire, library, park, or special districts.
Each sets its own rate, and the bill shows them line by line. See how to read a property tax bill.
Exemptions reduce the base
Homestead, senior, veteran, and disability exemptions reduce the taxable assessed value before the mill rate is applied. A $25,000 homestead exemption on a $200,000 assessed home in a 25-mill district saves $625 a year. See what is a homestead exemption.
Converting to percentages
Divide mills by 10 to get the rate as a percent of assessed value. 25 mills is 2.5 percent of assessed value. Some places express rates per $100 of value instead; a rate of $2.50 per $100 equals 25 mills.
Why mill rates change
Local governments set rates each year based on their budgets and the total assessed value in the district. When values rise after a reassessment, rates often drop to raise similar revenue, and the reverse. Your bill can still rise if your value increases faster than average.
Using mill rates when buying
Do not rely on the seller’s tax bill alone. After a sale, some states reassess to the purchase price, and exemptions may end. Use the current mill rate and an estimated new assessed value to project your own taxes.
Appeals
You cannot usually appeal the mill rate, but you can appeal your assessed value. See how to appeal property taxes.
Bottom line
A mill rate is a tax rate of one dollar per $1,000 of assessed value. Multiply taxable assessed value by mills and divide by 1,000 to estimate a bill, remembering that assessed value may be a fraction of market value and exemptions reduce it. Find assessor and tax offices via the Platbookmapper map.
What is a mill rate FAQ
What does one mill mean?
One dollar of tax per $1,000 of assessed value.
How do I calculate property tax from a mill rate?
Multiply taxable assessed value by the mill rate and divide by 1,000.
How do I convert mills to a percentage?
Divide mills by 10; 25 mills is 2.5 percent.
Can I appeal the mill rate?
Usually not, but you can appeal your assessed value.
Why did my mill rate go down but my taxes went up?
Your assessed value may have risen faster than the rate fell.