One-Rep Max Calculator
Estimate your one-rep max from any set with the Epley and Brzycki formulas, and get a full percentage-of-max chart to plan your training loads. Free, kg or lb.
Best for sets of 1–10 reps. Averages the Epley & Brzycki formulas.
How to use the One-Rep Max Calculator
- 1
Enter the weight you lifted and how many reps you did.
- 2
See your estimated 1-rep max.
- 3
Use the %-of-1RM chart to pick training weights.
- 4
Best accuracy comes from sets of 1–10 reps.
Frequently asked questions
Which formula do you use?
We average two trusted formulas — Epley and Brzycki — for a balanced estimate.
How accurate is it?
Very good for low-rep sets; accuracy drops as reps get high, so keep the set under ~10 reps.
What's the % chart for?
Programs often prescribe loads as a percentage of your 1RM — the chart gives you those weights instantly.
Tips & discussion
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