Jennifer R, a buyer for an online retailer that just picked up our University of Maryland college licensed t-shirts gave me a valuable lesson in mathematics. After three years in this business, she was quite surprised that I didn't know how to calculate profit margins. She'd probably also be quite surprised that I don't know the difference between net profits and gross profits, margarine and butter, and napping and sleeping.

So here's the math lesson. To calculate the profit margin of funny t-shirts (yes, this only works for funny t-shirts):

(Sale price of good-cost of good)/sale price of good. She wanted her margin to be 55%. Sounded good to me. We're just excited to spread the University of Maryland t-shirt love!