One-Rep Max Calculator
Use a set of 1–12 completed reps and a weight up to 1,000 in the selected unit. This is an estimate, not a recommendation to attempt a maximum lift. Changing units relabels the inputs; it does not convert weight.
Estimated one-rep max
- Estimated one-rep max
- 93.33 kg
How it works
Enter the load and the number of completed repetitions, then choose Epley or Brzycki. For one repetition, the estimate equals the lifted weight. Accuracy varies with exercise, technique and fatigue; higher-repetition sets generally give less reliable estimates. Inputs stay on this page.
Example
80 kg for 5 reps gives an Epley estimate of about 93.33 kg and a Brzycki estimate of 90 kg.
Frequently asked questions
Should I attempt the estimated weight?
Not based on this number alone. The estimate is not a safe-lifting prescription. Use appropriate supervision, equipment and a gradual training progression.
Do kilograms and pounds use different formulas?
No. The formula scales with the input weight and returns the same unit. Switching the unit changes the label only; enter the corresponding weight yourself.