The "property tax rate" is typically given as a percentage. It may be expressed as a per mil (amount of tax per thousand currency units of property value), which is also known as a "millage rate" or "mill" (one-thousandth of a currency unit). To calculate the property tax, the authority multiplies the assessed value by the mill rate and then divides by 1,000. For example, a property with an assessed value of $50,000 located in a municipality with a mill rate of 20 mills would have a property tax bill of $1,000 per year.