First - what not to do. Do NOT use the “subtract-and-divide” (SAD) method to figure out your bar math. Here’s an example - we want 110 lb on the bar (i.e., 110 lb total - including the bar’s weight), so we subtract the 45 lb bar from 110 lb, and we get 65 lb left over. We then divide 65 by 2 since we have to split that 65 lb between each side of the barbell to get 32.5 lb, and now we need to figure out how to load 32.5 lb on each side.
Again - do NOT do this. Mathematically, yes, it makes sense, but in the long run, it’s neither the easiest nor the quickest way to go about this process. We’ve seen people break out calculators to do this, and we’ve even seen people working some long division to accomplish this process, but no matter what tools you have at your disposal, SAD isn’t very practical, and it’s rather error prone as well.