One Rep Max Calculator

Estimate your 1RM using 5 proven strength formulas

Enter Your Lift

Enter the number of reps you completed (1-30). Results are most accurate for 1-10 reps.

How It Works

1. Enter Your Lift

Input the weight you lifted and the number of reps you completed

2. Multiple Formulas

We calculate using 5 established formulas and average them for the best estimate

3. Plan Training

Use the percentage chart to determine optimal training weights for each rep range