Quarterly Average Balance (QAB) is a requirement for certain savings accounts, and it is the average of all the closing day balances for any quarter. The QAB is calculated by adding the closing day balances and dividing the sum by the number of days in the quarter. For example, if the QAB of an account is Rs.500, the account holder needs to have at least Rs.500 in the account at the end of the day for the entire quarter. However, the account holder is not bound to maintain the same amount at the end of every single day in order to catch up with the QAB. Instead, the account holder needs to make sure that the average of daily closing balances over the quarter is equal to or higher than the prescribed QAB, not less. If the account holder fails to maintain the minimum balance, the bank may charge a penalty.