It depends on the investor.
An example: You buy a call on 100 shares of Acme at a $20 strike price, and you pay a $1 per share premium for it. Your intent is to make $100 profit, and to do so you'll have to sell the stock for at least $22 per share plus whatever your broker's commission is--if you have a broker that charges $10 for stock sales and $20 for exercising calls, you'll have to sell the stock for $22.30 per share to make your $100 profit.
If you are selling call options on stock you own (covered call) then there are two returns to think about: return-if-flat (meaning stock doesn't change between today and the option's expiration), and return-if-called (the return if the stock is called away from you). There are tools available to calculate both of these (see www.borntosell.com).