Maybe you think that you can just click and type formulas into a Pivot Table? Possibly you think that you can use formulas in Pivot Tables in the same way as you would usually enter formulas in Excel?
However, if you think that, you would be wrong. The reason is that you need to use what are known as Calculated Fields to write formulas in Pivot Tables in Excel.
Now if you want step by step instructions on how to do this, I can heartily recommend this how to add a calculated field to a Pivot Table guide.
In this way you will see how to calculate profit by subtracting the expenses away from the money received. You will also see how to work out how much profit you have made as a percentage.
Now, obviously, you need to create a Pivot Table. Before you do that, it would also be a good idea to create a Table. Even before you create a table you need to get your data structured correctly.