Mortgage
%
Monthly payment: $843.21
Yearly amount paid: $10,118.52
Total amount paid: $303,555.60
Total interest paid: $103,555.60
Equation
Monthly Payment = P * ( r * (1+r)^n / ((1+r)^n -1)
(P) Principal: The total amount borrowed for the loan.
(r) Interest Rate: Amount of interest per payment period.
(n) Number of Months: The number of payment periods in the loan.
Example
P = 10,000
r = 4% / 12 = .33333% or .0033333
20,000 * ( .0033333 x (1.0033333^60) / ((1.0033333^60) - 1)
20,000 * ( .0033333 x 1.22099 / (1.22099 - 1)
20,000 * ( 0.0040699 / .22099 )
20,000 * ( .0184167 ) = 368.33