One Rep Max Calculator
Calculate your max lift weight
Formula
Epleyw × (1 + r/30)
Brzyckiw × 36 / (37 − r)
Lander100w / (101.3 − 2.671r)
Lombardiw × r^0.1
w = weight lifted, r = reps performed
* Named after the exercise science researchers who developed each formula.
Training Intensity Guide
90–100%Max Strength / Testing
85–90%Strength Development
75–85%Hypertrophy + Strength
65–75%Hypertrophy
50–65%Muscular Endurance
FAQ
Is it safe to test my true 1RM?
For most lifters, estimating 1RM from submaximal reps is safer than actual 1RM testing. True 1RM testing should only be done with a spotter and after proper warm-up.
Why are results less accurate above 10 reps?
These formulas assume a linear relationship between reps and weight. At high rep counts, fatigue and muscle endurance factors become more significant, reducing accuracy.