# What is payment period, and why is it equal 100 in this mortgage table?

Here’s the table:

I think the payment period is a month, but I don’t understand why it’s 100.

The image is taken from this Excel exercise: http://web.utk.edu/~dhouston/excel/exer3.pdf

• did you follow the steps in the exercise? – mhoran_psprep Sep 28 '18 at 9:55

It is the 100th month of the mortgage term.

Using the PMT() function in Excel I generated this amortization schedule with the variables in your question:

For some reason rather than showing the whole amortization table they chose to let you calculate for any given month what the split between principal and interest would be.

Edit: Added the formula text in the next cell over on the top portion to show interest percentage used and PMT() function format.

• Your table is definitive. – user67265 Sep 28 '18 at 3:34
• Incidentally, when the Payment Period is 100 the Principal Paid is =(1+B5)^(100-1)*(B6-B5*B3) and the Interest Paid is =B6-(1+B5)^(100-1)*(B6-B5*B3) – Chris Degnen Sep 28 '18 at 8:44