I have outlined the information below to clarify how tax bills are determined and how filing a grievance can save you money, even if your tax bills increase. The example used below is based on an actual property's assessed value and taxes. Visit mynassauproperty.com and search for your property to see its Fair Market Value and Effective Market Value. Tax bills are calculated by multiplying the Effective Market Value (Assessed value) by the tax rates for that year. We can o