The time frame necessary to pay back a loan in full, including interest and principle, is known as the amortization period. The amortization period is the time frame required for a borrower to repay the whole principle balance of a loan along with the related borrowing costs (interest). Usually expressed in months or years, an amortization period is a time frame. According to a schedule called an amortization, the loan’s principle is paid down in regular, equal monthly installments. Each loan payment will include both interest payments and a part that will go toward the loan principal.