Convert Interest Rate into DecimalThe first step to calculating monthly mortgage payments is to convert the APR. The formula does not differ based on what the money is spent on but only when the terms of repayment deviate from a standard fixed amortization. M M Monthly payment n n Number of payments months The way these loans typically work is that every month you have an interest payment on the amount you owe on the loan principal.
Calculate Monthly Interest RateNext determine the monthly interest rate.
P B r12 1 r12m 1 r12m - 1. PMTC5 12 C6 12 - C9 When assumptions in column C are changed the estimated payment will recalculate automatically. The loan payment formula can be used to calculate any type of conventional loan including mortgage consumer and business loans. M M Monthly payment n n Number of payments months The way these loans typically work is that every month you have an interest payment on the amount you owe on the loan principal.