1RM Calculator
Estimate your 1RM for any lift.
How to use
- Enter your values in the fields above.
- Press Calculate to see your result instantly.
- Use the Share button to copy a link to your result.
About this calculator
Rather than risking injury by testing a true one-rep max, this calculator estimates it from a submaximal set using formulas like Epley (1RM = weight × (1 + reps/30)) or Brzycki (1RM = weight × 36 / (37 − reps)) — both built from the observed relationship between how much weight lifters can move for a given number of reps before failure.
Strength coaches, powerlifters, and bodybuilders use the estimated 1RM to program percentage-based training (e.g., 5 sets at 80% of 1RM for a hypertrophy block, or 90%+ for peaking strength work), and gym apps use it to auto-scale suggested weights as a lifter's numbers improve. Enter the weight lifted and reps completed to get the estimate.
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