Hi Chip!

Rate = 5%, PV = $500,000, Payment = $42,803.74. Using CUMIPMT
=CUMIPMT(Rate/12,12,PV,1,12,0), I get the correct amount of interest paid for
the 12 month loan ($13,644.89).

However using the NPER =ABS(NPER(Rate/12,Pmt,PV)) I get a result of only
11.43 months (instead of 12). While close, the variance worsens with lonnger
terms. In fact, the only way I am able to get a correct NPER calculation
result is when the Rate = 0%!

I appreciate your help. My goal is to develop a model where I can include a
variable in my calculation that will show how much I can shorten a mortgage
by adding a constant payment over and above the contractual amount. That
incremental payment will be applied directly to reducing Principal.

Thanks,
Ken Gorman

"Chip Pearson" wrote:

Post the formula you are working with, the values you are passing
to the formula, the result you get and the result you expect.


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com


"KG Old Wolf" <KG Old wrote in
message
...
I am using the NPER function to determine the number of periods
required to
pay of a loan at constant rate and constant payment. The
result is
consistently understated (periods are too few to pay off the
loan)

Is there a known problem? Has anyone else used this function?