1RM Strength Calculator

Estimate your one-rep max with multiple formulas

Enter Your Set

Weight Lifted Weight on the bar

Unit

Reps Completed Best with 1-12 reps for accuracy

RPE (Optional) Rate of Perceived Exertion (1-10)

1RM = Weight × (1 + Reps/30)

1RM = Weight × 36 / (37 - Reps)

Conservative, accurate for higher reps.

1RM = Weight × Reps^0.10

1RM = Weight × (1 + 0.025 × Reps)

1RM = (100 × Weight) / (52.2 + 41.9 × e^(-0.055 × Reps))