Borrowing base is an accounting metric used by financial institutions to estimate the available collateral on a borrower's assets in order to evaluate the size of the credit that may be extended. Typically, the calculation of borrowing base is used for revolving loans, and the borrowing base determines the maximum credit line available to the borrower. Occasionally, borrowing base is also used to determine the maximum size of a term loan. Depending on the contractual terms of the loan, the assets included in the calculation of the borrowing base may be used as collateral for the loan.