\[ \frac{T i}{1 - (1 + i)^{-n}} \]
Where:
T = Total Loan Payment
i = Effective Interest Rate (input is interest rate per YEAR while effective interest rate is per MONTH)
n = Number of Payments
\[ E = \frac{Q(1-(1+i)^{-n})}{i} - T \] \[ Q - E(1+i)^n \]
Where:
Q = Monthly Payment
T = Total Loan Payment
i = Effective Interest Rate (input is interest rate per YEAR while effective interest rate is per MONTH)
n = Number of Payments