1RM Calculator

Estimate your one-rep max using the Epley, Brzycki, and Lombardi formulas from any rep count.

Best accuracy at 1–10 reps. Estimates above 15 reps are less reliable.

1RM Calculator

Estimate your one-repetition maximum (1RM) from any weight and rep count using three established formulas.

  • Epley – weight × (1 + reps / 30) – most widely used
  • Brzycki – weight × 36 / (37 − reps) – accurate at 1–10 reps
  • Lombardi – weight × reps^0.10 – tends to give slightly higher estimates
  • The rep percentage table helps plan training loads at each intensity zone