To calculate whether you have a gain or loss on the sale of the property, you have to find out the FMV of the house on the date of your mother's passing (or an alternative valuation date if the executor chose one). Add to this FMV any closing costs, selling costs, capital improvements, special assessments and deduct any casualty losses you took as a tax deduction. This will be your cost basis in the inherited house. (This is called a stepped up basis in the property.) This is assuming you have not converted the property to a rental property.
Subtract your cost basis from the selling price to get your gain or loss on the sale of the property.
You cannot claim inheritance taxes as a deduction.
