a rate per thousand — taxes are calculated by using mill rates
The tax rate for real estate is usually expressed in mills. A mill is equivalent to dollars of tax per thousand dollars ($.001)of taxable value. Each municipality sets its own mill rate. Some municipalities also have different mill rates for different districts, as well as for school, water and sewer taxes. To obtain the tax for a property, divide the taxable value by one thousand and multiple this by the mill rate.
The amount of tax paid per dollar of assessed property value.
In reference to property taxes, a unit of taxation is a set ratio made by the city or municipal district.