If you want to calculate your total profit, our calculator will do it for you, but here we explain it. Once you already have the profit for one single t-shirt (for example, $30), that amount must be multiplied by the number of t-shirts you sold, for example, 145. It gives us a result of $4,350, but from that, you must subtract the expenses or investments you made, which, as we mentioned, are usually marketing. Let's say it is $937. Now, to calculate the final profit, we only have to do a small operation. From the $4,350, we will subtract the expenses, which are $937. This way, our final profit for selling 145 T-shirts will be $3,413.