Capital and Interest Computation

Capital Interest
  • Total Interest


Fixed monthly payment for a fixed rate mortgage

  • c: montly payments.
  • r: montly interest rate (since the quoted yearly percentage rate is not a compounded rate, the montly percentage rate is simple the yearly percentage rate divided by 12.)
  • N: number of monthly payment, called the loan “term”.
  • p: amount borrowed, known as loan’s principal.

In the standardized calculations used in US:


Amount owned this month = amount owned from the previous month + interest on this amount - fixed amount paid every month

1st term:

2nd term:

3rd term:

Nth term:

As at the Nth term, the payment is done, we have