What is em scaling?

em scaling is a method of sizing elements on a web page relative to their parent container's font size. It is a popular approach for responsive web design because it allows designers to easily adjust the size of individual elements as the viewport size changes, rather than having to manually specify each size.

An em is a unit of measurement in typography that represents the width of a capital letter "M" in a given font. On the web, 1 em is equivalent to the font size of the element's parent container. For example, if the font size of the parent container is 16 pixels, then 1 em for any child element would also be 16 pixels.

Using em-scaling, a designer can set the font size of the body element in relation to the viewport size, and then size all other elements on the page using ems. This results in a consistent visual hierarchy that adapts to different device sizes.

One of the benefits of em-scaling over other units of measurement is that it can make a web page more accessible. If a user has a larger or smaller font size set in their browser, all elements on the page will scale proportionally, maintaining their relative sizes and positions. This is especially important for users with visual impairments who may require larger font sizes to read content.