From Microsheet Systems:
Easily calculate your payment, interest, or how much you can afford (mortgage amount). The workbook has 2 prepared automated spreadsheets to help you compare up to four loans or mortgages in the same time. See your financial summary after certain amount of years in the same sheet as well. A second sheet is to help you compare fixed mortgage rate to variable mortgage rate and instantly see the differences. Both sheets display amortization schedule for you to explore the details. Also, four payment methods are supported: Weekly, Bi-Weekly, Bi-Monthly, and Monthly. Add pre-payment and see instantly the effect of your extra payments in term of total interest paid and number of payments saved.