There are a few ways to see how much your bowling ball weights. First off, most bowlers tend to stick with one weigh of bowling balls. I bowl with 15 LBS bowling balls and all of them are 15 pounds, so I know the weight just from that. If you are buying a, the weigh of the ball will be on the box. Most bowling shops displays bowling balls on their shelves, they are mostly 15 pound bowling balls. If you are buying a used bowling ball, then the person that is selling you the bowling ball should know the weight. Most bowlers tend to stick with one weight and most bowlers bowl with a 15 pound ball. If theses don’t work, then try putting the bowling on a scale to see the weight. I would use a bowling cup so the ball can stay still while you weigh the ball.