I came up with this property tax calculator to estimate the cost of my real estate taxes using different assessment numbers. I wanted to know if it was worth the effort to appeal my Allegheny County property assessment. Real estate agents should find this calculator useful to estimate the property taxes on their listings. Prospective home buyers can estimate the real estate taxes based on a new sales price. Enter the FULL MARKET VALUE AND COUNTY ASSESSED VALUE as presented by the Allegheny County lookup Assessment page. You can change the real estate tax millage numbers by backspacing out the entered value and typing in the correct millage rate. I encourage you to verify the correct tax rate for the municipality and school district, because it's too difficult to maintain the exact millage rate for each taxing body. The use of this calculator is intended for illustrative purposes only. No warranties are expressed or implied (last updated 9/2013). Learn more about property assessment and real estate taxes for Allegheny County.