I'm trying to calculate equal payments for loans charging daily rates with different periods.
If the periods are exactly the same i.e. 30 days, I can use a formula to work out the repayment amounts without a problem. However, I've not yet found the perfect solution to my problem.
In order to understand what I need to do I've created a spreasheet that shows the steps I'm currently taking.
Step 1 - is to compound the interest and work out a final balance as if no repayments were made. Although the rate here is equal, this allows me to vary the rate if necessary to immitate different interest periods.
Step 2 - calculates the running balance using the max repayment from step 1, resulting in an overpayment.
Step 3 - I take the overpayment, divide it by the number of perds and then adjust the previous repayment. I loop through over/underpayments until the result is 0 (or near).
Whilst this currently uses a spreadsheet - the final code would be used in a program. However I can't help but think there are shortcuts to be made using tried and tested formulas.
Any advice appreciated.
P.s. I'm not a maths wizard!