There are multiple different ways to calculate the diagonal of a square. The simplest and easiest way to calculate the diagonal of a square is to use Chippy Tools by simply ending the side length. If using the calculation to check if a constructed structure is square it is recommended that the length and the width are independently measured to provide the expected diagonal measurement. Chippy Tools makes the calculation quick and simple hiding the complexity of Pythagoras's theorem that is uses is the background.