Bench Press Calculator – Calculate Your 1 REP MAX Brian E. May 22, 2013 Tools SuppNation’s bench press calculator can be used to give you an estimate of what your 1 Rep Max bench press would be. Now, these figures aren’t 100% accurate, so don’t go out and try to bench press 500lbs, but have fun with it and brag to your bros. The way this bench calculator works is it takes the amount of weight you can bench for a certain number of reps and uses a formula to calculate your approximate 1 REP MAX. To use the bench press calculator simply enter the weight in the first box provided and select the number of reps from the drop down box. For example, if I benched 225 pounds for 20 reps I would enter 225 and select 20 reps. The bench press calculator works in both pounds and kilograms (for folks across the pond). Leave a Reply Cancel Reply Your email address will not be published.CommentName* Email* Website To leave a comment please enable JavaScript in your browser settings!