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.

Thanks in advance for your answers!
Robert