Gross NPA is the summation of all loan assets that are classified as NPA as per RBI guidelines. When the NPA occurs, it is not just an interest income loss to the bank, but a principal loss as well. That means, if a bank has lent Rs.100 to a company with an outstanding loan amount of Rs.80, then the bank would lose this 80 along with the future interest payments as well when the company does not repay back.