Guides

Short, sourced explanations of the numbers behind the calculators.

• 1RM Formula Guide

  The six one rep max formulas side by side, rep by rep: where each reads high or low, why they disagree, and when an estimate stops being reliable.

• How to Test Your 1RM Safely

  A step-by-step protocol for testing a true one rep max, based on NSCA guidance: who should test, how to warm up, how to choose attempts, and when to stop.

• Methodology

  Exactly how every number on StrengthCalc is calculated and rounded.