One Rep Max Calculator
Estimates your theoretical one-repetition maximum lift using the Epley formula.
Lilu Baba's One Rep Max Calculator estimates your theoretical 1RM from a lighter, safer set using the widely-used Epley formula. Informational only — always use proper form and spotters when testing strength limits.
How to use this calculator
- Enter the weight you lifted.
- Enter how many reps you completed with that weight.
- Your estimated 1-rep max updates instantly using the Epley formula.
Estimated One Rep Max (kg)
—
FAQ
One Rep Max Calculator — frequently asked questions
1RM = Weight × (1 + Reps ÷ 30).
No — it's a well-tested estimate, but individual results vary, especially at very high or very low rep ranges.