You know you want to do bench presses, but you're not sure what barbell you need, or what will fit your rack.
You came to the right place! Here's how you figure it out.
First, if you already have a bench with attached bar holders, or a power rack, measure it. What you want to measure is the width of where the bar is going to be sitting on the rack. . See the diagram to the right. Be sure to measure from the outside of one side to the outside of the other, not just the space inside. So in total you're measuring: