One Rep Max Calculator

Seven 1RM formulas, rep-max tables, percentage training loads, and RPE-adjusted estimates from a single submaximal set.

How It Works

  1. Enter weight and reps. Log a recent set (1–12 reps) — heavier sets with fewer reps are most accurate.
  2. Get estimated 1RM. Epley and Brzycki averages are shown; compare all seven formulas side by side.
  3. Rep max table. See predicted weight for each rep count at your calculated 1RM.
  4. Training percentages. Build loads from 100% down to 50% with estimated rep ranges.
  5. RPE adjustment. Enter RPE and reps to back-calculate e1RM from a submaximal effort set.

Also try our RPE Calculator or Fitness & Health Calculators.

Enter values to see results.

Formula & Reference

1RM ≈ Weight × (1 + Reps/30) · Brzycki · Lander · +4 more