One Rep Max (1RM) Calculator

Estimate 1RM, then use goal-based recommended percentages with sets/reps and RPE.

Units
Estimated 1RM
Enter weight + reps, then calculate.
Show formula breakdown
  • Epley
  • Brzycki
  • Lombardi
  • Mayhew
  • O’Connor
  • Wathan

Best estimates come from near-failure sets in the 2–10 rep range. Above ~12 reps becomes less accurate.

Recommended training percentages

Choose a goal. We’ll only show the most useful % ranges for that goal.