Originally Posted by Drew Eckhardt

3. Most manufacturers have at least two cuts - race fit which tapers more in the waist, and club which fits more like a T-shirt. Some have a lot more - Louis Garneau has relaxed fit, comfort fit, standard fit, racer fit, and aero jerseys which stretch to fit. Standard is about like some companies' race fits. You want a looser fit.

Top to bottom - LG aero, racer-fit, standard all the same size. The more relaxed fits add 2-4 inches in circumference to standard fit.