Hello: I am stuck on what should be a simple simple calculation. I want create a loan amortization table that breaks down and displays the principle and interest payments per period for a mortgage. Currently I am using two separate formulas (PPMT and IPMT) which calculate the principle and interest for a given period.  There is a 2 dollar difference that I cannot account for between the sum of these two numbers and the actual payment which is another small frustration. However, the real problem is that I want to see the effect of changing the payment amounts. The way it is working now the payment amount is automatically calculated within the formula given the number of periods and interest rate etc. that I have entered.   The work around is to simply apply any money over the needed payment directly to the principal but this theory doesnąt work so well when the payments are less than the required amount. In any event I assumed when I installed the Analysis pack that there would be a formula for that which allowed the payment to be referenced from another cell.  Is there no such thing.  Any suggestions would be welcomed. I have a feeling this is a very easy problem and I am just blind.  Please advise. Thank you in advance. Scott

Loan Amortization Table -How?filenewnew from templateloan.xltunprotect sheetchange payment column as desired.