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FAQ

1RM is the heaviest weight you can lift for exactly one repetition with good form.

Most accurate for 1-10 reps. The higher the rep count, the larger the estimation error.

Roughly 85-95% for strength, 67-80% for hypertrophy and under 65% for muscular endurance.

About this tool

This one rep max calculator helps gym-goers and powerlifters estimate maximal strength without risking a true max attempt. Enter the weight lifted and reps completed to compare five proven formulas, get an averaged 1RM, and read the percentage table that maps training loads to rep ranges for squat, bench press and deadlift programming.