One-Rep Max (1RM) Calculator (Epley, Brzycki formulas)

Your One-Rep Max (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise. It's a common measure of strength.

Since testing a true 1RM can be risky, several formulas have been developed to estimate it based on the weight you can lift for multiple reps. This calculator uses two of the most popular and scientifically validated formulas:

Epley Formula:
1RM = Weight * (1 + (Reps / 30))

Brzycki Formula:
1RM = Weight / (1.0278 - (0.0278 * Reps))

Note: These formulas are most accurate for rep ranges between 2 and 10. The higher the reps, the less accurate the estimate may be.