One-Rep Max Calculator

Estimate your one-repetition maximum from a weight lifted for a number of reps, using six published formulas. Includes a per-formula comparison and a percentage-of-1RM table for setting rep targets. Runs locally.

Weight lifted

Reps

Unit

Percentage of 1RM (average estimate)

%1RM	Weight	≈ Reps

Estimates are heuristic — true 1RM varies by lift and individual. Epley and Brzycki agree well for 1–10 reps. Runs locally.