When you enter a buy put options trading strategy, just like any other strategy, you need to know at which point you are profitable or at which point you are absorbing a loss. The following formula allows you to calculate your breakeven point in a buy put option scenario.

Breakeven Price = Strike Price - Premium Per Stock

If you have a put option, it will be profitable when the underlying stock price falls passed the breakeven point. If that does not happen by the expiration date then the put option will not make a profit.