1RM Percentage Calculator

1RM Percentage Calculator

Most strength programs prescribe loads as a percentage of your one-rep max — 5×5 at 80%, a top single at 90%, back-off sets at 70%. Enter your 1RM and this calculator builds the full chart from 100% down to 50%, with the exact weight (rounded to real plate increments) and the typical reps at each percentage. Use it to set every working weight in a 5/3/1, percentage-based or linear program at a glance.

The rep ranges are a general guide; the reps you can actually do at each percentage vary by lift, training level and fatigue. Most programs prescribe work in the 70–90% range, with the lower end for volume and the higher end for strength.