As @DoninGA stated on a different post:
The Adjusted Basis of the home is the original purchase price plus certain settlement fees paid at time of purchase and the cost of any improvements made to the home prior to the sale.
You know how much you paid for the house originally. That is $x.
You know how much you spent on improvements to the property $y.
You know how much you paid to sell the property with realtor fees, etc, $z.
Your costs basis is $x +$y + $z.
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