For the client, it is only relevant to know the overall price they need to pay, so breaking down your fee is not necessary.
If you're going to specify percentages, your price might suddenly seem more expensive to the client. This can lead to a discussion with some clients over a fee that can simply be justified.
Keep it simple for the customer, enter your price into the calculator and state the buy out that is applicable (e.g. "I'm charging € 1000 for an online commercial that can be broadcast for 12 months in France).
Calculation to know how much you must charge the client:
YOUR fee / 0.75 = CLIENT fee
For example: € 600 / 0.75 = € 800
Calculation to know how much you will receive from the client (if they suggest a fee first):
CLIENT fee x 0.75 = YOUR cut