Estimate your one-rep maximum based on the weight and reps you can perform
Your one-rep max (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise. This calculator estimates your 1RM using two validated formulas based on the weight you can lift for multiple reps. The Epley formula is widely used in strength training, while the Brzycki formula provides a useful comparison point.
The Epley formula calculates 1RM as weight lifted multiplied by 1 plus reps divided by 30. The Brzycki formula uses a different approach: weight times 36 divided by 37 minus reps. Both are well-established in exercise science literature.
The Epley formula tends to be slightly more accurate for higher rep ranges (above 5 reps), while the Brzycki formula is often preferred for lower rep ranges. Both provide reasonable estimates, but for the most accurate 1RM, performing an actual max lift with proper form and a spotter is recommended.
Yes, the 1RM formulas work for any major compound lift such as bench press, squat, deadlift, overhead press, and bent-over row. However, these formulas are most accurate for exercises that recruit large muscle groups and follow a standard repetition pattern.