Adjustable rate mortgages can provide attractive interest rates, but your payment is not fixed. This calculator helps you to determine what your adjustable mortgage payments may be. "> This Financial Calculator requires a Browser with Java Support Definitions Mortgage amount Original or expected balance for your mortgage. Starting interest rate Initial annual interest rate for this mortgage. Term in years The number of years over which you will repay this loan. The most common mortgage terms are 15 years and 30 years. Interest rate cap This is the highest interest rate allowed by your mortgage. Your actual interest rate will not be adjusted above this rate. Expected adjustment The amount you believe that your mortgage’s interest rate will change. This amount will be added to or subtracted from your interest rate. Months between adjustments The number of payment periods between potential adjustments to your interest rate. The most common is 12 months, which means your payment could change at most once per year. Starting monthly payment Monthly principal and interest payment (PI) based on your beginning balance and starting interest rate. Total payments Total of all monthly payments over the full term of the mortgage. This total payment amount assumes that there are no prepayments of principal. Total interest Total of all interest paid over the full term of the mortgage. This total interest amount assumes that there are no prepayments of principal.