I have a problem when I try to calculate monthly repayments on loans. I use the formula:

K0 * i*(1+i)^n

-----------

(1+i)^n -1

The problem is that my calculations are slightly higher than those on the banks and comparison sites'.

ie. K0=7500, i=8.9%, n=48

With those values I get a monthly repayment on 186.28

The banks and comparison sites gets a value on 185.05

What is wrong with my formula?

And how do you calculate with deferment/payment holidays?

Thanks,