One-Rep Max Calculator (Free)

Estimate your one-rep max from a set of 1 to 10 reps.

  1. Units
  2. Weight lifted
  3. Reps completed
How it works

Epley: 1RM = weight x (1 + reps / 30). Brzycki: 1RM = weight x 36 / (37 - reps). A single rep returns the weight you lifted. Both are estimates, and accuracy drops as reps go up, so this tool accepts 1 to 10 reps. A heavy set of 3 to 5 reps usually gives a closer estimate than a set of 10.

Results are shown to 0.1 and rounded to the nearest 5 lb or 2.5 kg for loading.

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