This is a CSS tutorial to draw concentric circles using pure CSS. Here Web Developer Mr Choudhury shown with free source code examples, the easiest ways to draw CSS circles & concentric circles with the help of pure CSS. Here DIV represent each circle having border-radius:50%;.
About this tutorial & author : Also Mr. Choudhury shown the formula, and he described and explained here developed by the renowned CSS layout expert and css template designer for web page layouts.