I need a way to get the compound interest in open office calc, so do any functions already exist for such?
There is a function
There are many financial functions in OpenOffice.org Calc, but you need to be very clear about exactly what kind of "compound interest" transaction you are trying to calculate.
I wanted to calculate the compound interest payable on a loan where I made no payments, and let the balance accumulate. That is, each period there is interest on the cumulative balance due, and that interest gets added to the total gets added to the cumulative balance due. Calc appears to have no function for this case. However, if you know the maths, it is simple to write the formula using the
Here is the formula to calculate the amount of a loan with compound interest, with explanation of parameters:
It's common to have a loan with an annual interest rate, compounded monthly. The same formula applies, but for rate be sure to use the interest rate per year divided by 12, the number of months per year. So, if the interest rate is 12% per annum, then for the rate parameter use 12% / 12 = 1% per month.
The formula above gives the total amount of the loan. To get just the compound interest portion, subtract prin from the above formula.