Percent of 1RM Calculator

About this calculator

Training programs commonly prescribe loads as a percentage of one-rep max (%1RM) — the heaviest weight a lifter can lift for a single complete repetition — because it standardizes intensity across lifters of different strength levels; a percentage-based prescription scales automatically to each individual's actual capability, unlike a fixed weight.

Strength coaches and periodization models, such as linear or undulating periodization, use %1RM ranges to target specific training adaptations: roughly 85 to 100% 1RM for maximal strength and low-rep power work, 67 to 85% for hypertrophy-focused moderate-rep training, and below 67% for muscular endurance and technique work, often cross-referenced against the Epley or Brzycki rep-max estimation formulas when a true 1RM hasn't been tested directly.

This calculator takes your one-rep max and a target percentage and returns the exact training load to use for that set.