Calculate your one rep max for any lift. Uses 6 proven formulas and shows your full strength training percentages.
Enter the weight you lifted and how many reps you completed — not to failure, just your working set. The calculator uses six established formulas and averages them for the most accurate estimate.
Your one rep max (1RM) is the maximum weight you can lift for a single repetition with proper form. It's the foundation of strength programming — most training percentages are calculated from your 1RM.
This calculator uses the Epley, Brzycki, Lander, Lombardi, Mayhew, and O'Conner formulas. Each has slightly different accuracy at different rep ranges. The average of all six gives the most reliable estimate across most athletes.
Strength training is typically programmed at 70-95% of your 1RM. Heavy singles fall at 90-100%. Hypertrophy work is usually 65-80%. Technique work stays at 50-65%. Knowing your 1RM means you can program every session with precision.