I am having problems with what I think should be a fairly simple calculation but I'm not sure what I'm doing wrong. I have a debt value. Interest is calculated on that debt value. Every 6 months, the cumulative interest is added to the debt value and the interest for the next 6 months is calculated on the new debt balance.
In the screenshot below, the opening debt value holds the original amount. Revised debt value returns the cumulative interest at the required date. Rolling adds them together. The circular reference comes when I try to calculate the Interest from the rolling debt value. Any ideas how to resolve this would be gratefully received!