I've searched the archives of the group and looked at A LOT of posts
regarding the IPMT function, but I'm just not seeing a concrete answer
to this very simple problem..

I am doing basic interest calculations on loan amounts to compare
various options, but the values I'm coming up with are different than
what I get with an amortization schedule.

For example, a $100,000 loan, 5.5% per year, 180 total payments - what
is the cumulative interest at the end of the first year? According to
my amortization schedule it is $5389.81. However, if I use the
function:

=IPMT(0.055,1,180,100000) the result is $5500.00

Its a minor difference, but I can't figure out how to get these
numbers to reconcile. Can anyone tell me where I am going wrong and
what method/formula to use to make them equal?

Thanks very much.