One Rep Max Calculator: Calculate your strength with the Ultra Crazy Runner Strength Calculator®

Ultra Crazy Runner One Rep Max Calculator

How to Use the Ultra Crazy Runner One Rep Max Calculator. This tool helps you estimate your 1RM for a specific lift based on the weight you can lift for a given number of reps. Here’s how to use it: Choose your lift, select the unit, enter weight lifted, enter number of reps. Body weight is optional so you can find the percentage of your body weight lifted.