1RM Calculator (One Rep Max)

Use this free 1RM calculator to estimate your one-rep max based on the weight and reps you performed. This tool is ideal for strength training, powerlifting and strongman athletes who want to calculate training percentages accurately.

1 Rep Max Calculator

kg lbs

Weight lifted Reps performed RPE (optional, 6–10)

If RPE is provided, calculator uses RPE-based estimation. Best accuracy ≤10 reps.