Hi,



I'm taking my first ever finance subject this semester and am having some trouble.



Does anyone know how to calculate the "net profit margin"?



The equation I have is net profit/sales.



My question is, for the company I'm looking at the financial statement gives revenue, should I use this, or should I just use the sales? The company must have some income from another source (interest?)



Any ideas?



Also having trouble with "Interest expense"



The equation is (net profit + income tax + interest)/ interest expense.



Is the interest on the top line the same as the interest expense?



Thanks!