One Rep Max Calculator

Estimate your 1RM for weightlifting exercises.

Weight Lifted (kg/lbs)

Reps Performed

Estimated 1 Rep Max

Based on Epley Formula

What is this Online One Rep Max Calculator for?

The One Rep Max (1RM) Calculator estimates the maximum amount of weight you can lift for a single repetition based on a set of multiple reps. It is safer than testing a true 1RM.

How does it work?

It uses the Epley Formula, a widely accepted equation in strength training: 1RM = Weight × (1 + Reps/30).