Estimate your one-rep max from a set you can already lift, with a percentage table for planning your working sets.
Estimates your one-rep max from a set you can already do. Accuracy is best at about 10 reps or fewer. The percentage table is a common guide for planning working sets. The weight unit is whatever you type, kg or lb.
Your one-rep max (1RM) is the most weight you can lift for a single repetition of an exercise. It is the standard reference for how strong you are on a lift and for setting training loads as a percentage of it.
Rep-max formulas are good estimates, especially for sets of about 2 to 10 reps. Accuracy drops as the rep count rises, because endurance starts to matter more than pure strength. The tool averages the Epley and Brzycki formulas.
Training programs often prescribe a percentage of your 1RM, for example 5 sets of 5 at 80%. The table converts your estimated max into those working weights, with rough rep guides for each percentage.