One Rep Max Calculator
Estimate the maximum weight you can lift for one repetition.
Result
Results are estimates for general information only and are not professional advice.
Your one rep max
Your one-rep max (1RM) is the most weight you can lift once. This calculator uses the Epley formula to estimate it from a set you performed, and shows useful training percentages (95%, 90%, 85%…).
Frequently Asked Questions
What is the One Rep Max Calculator?
Estimate the maximum weight you can lift for one repetition. It runs instantly in your browser and is completely free.
Is the One Rep Max Calculator free and does it require signup?
Yes. Every calculator on Calculatis is 100% free with no registration, and the values you enter are never stored.
How accurate is the One Rep Max Calculator?
It uses standard, widely-accepted formulas. Results are reliable estimates for general use and are not a substitute for professional advice.