How much interest can you save by increasing your mortgage payment? This financial calculator helps you find out. Click the "View Report" button to see a complete amortization payment schedule, and how much you can save on your mortgage! "> This Financial Calculator requires a Browser with Java Support Definitions Annual interest rate (APR) The yearly cost of a mortgage, including interest, mortgage insurance, and the origination fee (point(s)), expressed as a percentage. Maximum APR is 20%. Mortgage length (years) Total length, or term, of your original mortgage in years. Most common lengths are 30 years and 15 years. Original mortgage amount The original amount financed with your mortgage. Not to be confused with the remaining balance or principal balance. Additional monthly payment Your proposed extra payment per month. This payment will be used to reduce your principal balance. Scheduled payment Monthly principal and interest payment (PI) based on your original mortgage amount, term and interest rate. Accelerated payment Scheduled payment plus additional monthly payment. Total savings Total amount you would save in interest if you made the accelerated payment until your mortgage was paid in full.