Needs solving: Circular Calculation Error

Hi, I need help with this excel circular formula issue. I am to automate something that seems impossible to an excel noob like me.

While doing budgeting for a project, I have to account for our Profit Margins, Contingencies and kick backs. Meaning whatever the contract sum is after adding profits and contingencies, I have to account for 5% that goes to kick backs, and include that into our costing as a FINAL contract sum.

Since the FINAL contract sum is tied to the 5%, there is a circular error. As a temporary fix, via trial and error, I had to manually input 6.325% as the actually mark-up to account for the 5%.

Is there a way to automate this process? Is it even possible?

Unfortunately, I can't add a picture to demonstrate my problem.