One Rep Maximum Effort Calculator

This calculator will give you an approximate one rep maximum effort based on the weight you lifted and the number of reps you lifted it. You can enter up to 10 reps, but note that as you enter higher reps results become less accurate due to non-strength related physiological factors that are involved in the lift, such as muscular endurance, mental focus, energy levels, muscle fiber types, and so forth.

To begin, enter a weight you lifted, how many reps you lifted it, and then select whether it was one of the big three. If it was not, choose "Other".