Formula Used
Monthly payment = P × [r(1 + r)^n] ÷ [(1 + r)^n − 1]
P = principal, r = periodic interest rate, n = number of payments.
How the formula is applied
The calculation links Loan amount ($), Interest rate (%) and Loan term (years) to monthly payment. The amortizing payment covers both interest and principal. Total interest is the sum of scheduled payments minus the modeled principal.