One-rep max calculator

Weight lifted

Unitpoundskilograms

Reps completed (1 to 10)

Calculate

How it works

Enter a weight you lifted for between 1 and 10 clean reps. The calculator averages two common formulas, Epley (weight × (1 + reps ÷ 30)) and Brzycki (weight × 36 ÷ (37 − reps)), then shows working weights from 60 to 95 percent of that estimate.

Using the percentages

• Heavy strength work often sits around 80 to 90 percent for low reps.
• Moderate loads around 65 to 75 percent suit higher-rep work and warmups.
• Estimates are most reliable on compound lifts and with sets taken close to failure with good form.

Stay safe

Do not test a true one-rep max without a spotter or safety bars, and warm up thoroughly. If you are new to lifting, a technique-focused routine is better than maxing out. See our medical disclaimer and plan your sessions with the weekly planner.