Question: calculate how much mortgage left to pay?
Answer: The formula goes like this: B = (PMT/R) x (1 - (1/(1+R)^N) In the formula, "B" is the principal balance, "PMT" is the monthly payment for principal and interest and "N" is the number of months remaining. "R" is your interest rate, but it's expressed as a monthly rate rather than an annual one.