One Rep Max Calculator
Estimate your one-rep max (1RM) from weight lifted and reps completed. See training percentages.
lbs
Estimated 1RM
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95% (2 reps) —
90% (3-4 reps) —
80% (7-8 reps) —
70% (12-15 reps) —
How to Use This Calculator
Enter the weight you lifted and how many reps you completed. The calculator estimates your one-rep max using the Epley formula and shows training weights at various percentages.
Formula
Epley Formula: 1RM = Weight × (1 + Reps / 30)
Training percentages: 95% (2 reps) | 90% (3-4 reps) | 80% (7-8 reps) | 70% (12-15 reps)
Training percentages: 95% (2 reps) | 90% (3-4 reps) | 80% (7-8 reps) | 70% (12-15 reps)
Example
Example: Bench press 185 lbs for 5 reps: 1RM = 185 × (1 + 5/30) = 216 lbs. Train at 80% = 173 lbs for 7-8 reps.
Frequently Asked Questions
- Your one rep max is the maximum weight you can lift for a single repetition with proper form. It is used to program training intensity as a percentage of 1RM.
- The Epley formula is most accurate with 2-10 reps. Above 10 reps, estimates become less reliable. For best accuracy, use a weight you can lift for 3-5 reps.
- Strength: 85-100% (1-5 reps). Hypertrophy: 67-85% (6-12 reps). Endurance: 50-67% (12-20 reps). Warm-up: 40-60%.
- Direct 1RM testing carries injury risk. Estimating from submaximal sets is safer and nearly as accurate. Only test directly with a spotter and proper warm-up.