Problem with solving a budget

Hi!

I have trouble finding a solution to a problem regarding a budget. I have to list a 10% guarantee as a cost when calculating earnings. But my problem is that the guarantee is dependent on earnings and should be 10%. I can solve the problem below to get X=X by many trials and errors, but would have been even better to get excel to output this straight away. But I havent gotten around the problem with circle references. Anyone have any suggestions? Any help is much appreciated!

+ Income	1000
- Costs	500
- Guarantee (10% of Earnings)	X
= Earnings	500
10% of Earnings	X

Hi

I think your questions is as much mathematical as is it Excel formula related. Maybe the following will help ...

If Earnings = "Y"

Income - Costs - 10% Y = Y
Income - Costs = Y + 10% Y
Income - Costs = 1.1 x Y

So ... Y = (Income - Costs) / 1.1

In your example Y = 454.54

10% number can change and you can add that as a fixed variable in your formula.

Does that help?

Stephen