Finances - percent expenses

I’m adding a percentage for monthly expenses - should these be deducted off of the gross revenue, or the total remaining after all expenses, etc have been calculated?

I’ll have to ask my girl but she’s not around (accounting major haha), but maybe some of you have direct experience?

as far as i remember its calculated in the gross revenu.

but itsq bin a long time so i can be wrong.

gr joeri