Options Profit Calculation

The profit you make on an option (or anything) is the amount of money you receive minus the amount of money you pay. From your example, if the price goes up to $50 and you exercise the option, you'll be able to sell the stock for $50/share. You'll have paid $7.55 for the option plus the $40 strike for a total of $47.55. So if you subtract that from the $50 you can get by selling the stock, your profit is $2.45 per share (each contact is for 100 shares).

This formula is the general formula you'd apply to calculate your profit or loss:

Final stock price - (option price + strike price + fees).

If that value is positive, it signifies a profit. If it's negative, a loss. And the stock price that makes the formula come out to zero is the break-even price. Note, though, that you'll never lose more than the option price because if the stock price falls below the strike, you won't exercise the option.

No one can answer your question because you did not specify the expiration. Since Robinhood averages the bid and the ask when providing their data and since I peeked at the option chain, it appears that you're looking at the August $40 call.

The cost of acquiring the stock when buying a call is the strike price plus the cost of the call. That's $40 plus $7.55 so Robinhood is correct in that the break-even price is $47.55.

To evaluate what an option will be worth at any given time and price prior to expiration, you need an option pricing formula. You can download one for Excel or you can use a web site such as this one to calculate it yourself.

Note that future implied volatility of an option is unknown and it will vary between now and expiration. The IV of your call is very high at about 100. If it were to drop to 50 in the next few days, your call would lose half of its value. If it were to drop to 50 halfway until expiration, your call would lose 5/6 of its value. And obviously, your call would appreciate if IV increased. Therefore, it's imperative that you understand this component of option pricing. We've had questions here asking for example, "How come my stock went up 5 points this week and my call lost money?" How come? (Hint: Look at the IV).