On Jul 5, 3:36Â*am, Robert Golja
wrote:
I have an annuity plan for let's say 5 years with 60 monthly installments
with a financing amount of 10.000 ‚¬ and 10 % interest rate. The payment plan
starts in March 2007. Is it somehow possible to calculate with a formula, how
much interest I will have to pay just for the periode from March till
December in the first year? That means only for 9 month.

=CUMIPMT(10%/12, 60, 10000, 1, 9, 0)

If you get a #NAME error, look at the CUMIPMT help page for how to
install the Analysis ToolPak add-in.

If the ATP is not available to you, the following will compute the
total interest for the first 9 months, but not for any arbitrary
period:

=9*PMT(10%/12, 60, -10000) - (10000 - FV(10%/12, 9, PMT(10%/12, 60,
-10000),-10000))

Note: These formulas assume that monthly interest is computed by 10%/
12; that is, that interest compounds monthly.

PS: It is not difficult to modify the second formula to handle an
arbitrary period. But I think it is not worth over-complicating it
since I think (hope) it is unlikely that you will use it.