=PMT(1.5%/12,312,0,8500) The rate argument is 1.5% divided by 12, the number of months in a year. The NPER argument is 312 for twelve monthly payments over three years.
Fortunately, Excel can be used to create an amortization schedule. The amortization schedule template below can be used for a variable number of periods, as well as extra payments and variable interest rates.