Multiple formulas
Compare estimates from Epley, Brzycki, Lombardi, and O'Conner calculations.
Free strength calculator
Estimate your one-rep max from a completed set
Enter the weight and repetitions from a recent set to compare common one-rep-max formulas and view useful training percentages.
Training percentages
Translate an estimated max into practical loading targets from 65% through 100%.
No account required
Use the calculator for free, then log the result with your workouts if you choose.