For a detailed explanation of the rules for determining cost basis of a gift, see our website page: I Received a Gift.
In most cases, your cost basis will be whatever the cost was in the hands of the donor. However, there are situations when this rule does not apply.
626 Landmark Foundation
You can use our calculator to determine the cost basis for your gift if you know the fair market value on the date of the gift and the cost basis of the donor.
If the fair market value at the time of the gift was less than the donor's cost basis, you will not be able to know your cost basis for sure until you sell it! That is because your cost basis for a loss will be different from your cost basis for a gain.
Click on the image below to access the gift calculator