This is a tool which can convert pixel to em and vise versa. Set Base Pixel then type in either px or em under Input Source to convert to the other.
What is an EM?
With each complex feature in CSS, you will always have that turning point once you see how powerful and commanding the feature is. Believe it or not, some people’s turning point with ems happens long after they wrote a pun-filled overture to the subject.
In CSS, an em is equivalent to the calculated font size for the element to which it is used or applied. Once em units are affirmed on child elements that do not have defined font size, they will take over their font size from their parent, or another forerunner element, perhaps going back to the origin element on the document.
An em is a unit of measurement in the field of typography. It is equal to the height of the type size being used. If a website’s font is 16 pixels, then 1em is equal to 16px.
A pixel is a solid unit of permanent size, and it’s not made for fonts that are generally illustrated in Point. Pixel is a measurement which must never be utilized for text as it is worthless for text. It’s like measuring weight using centimeters and inches.
Point and Pixel are permanent sizes. Some users have pitiable eyesight or perhaps sit farther away from the monitor. Permanent sizes see the size of the text to something you want and not what users needs or wants.
EM and % are flexible units based on the selected size and font the users have in their browser. So, meaning every user will see the size they picked and not as they chose it. The size of the text can be modified to fit their needs and wants as it is incredibly flexible.
However, that has its price, and you should make your site to be flexible too. Typically, you utilize em for text and pixel for a thickness of structural elements. But, if you made a menu flexible, the box which holds it should be flexible to stretch with it or at bigger sizes of text.
PX to EM formula
em = pixel / base pixel
If base pixel is 16 and we need to convert 13px to em, then we have
13px / 16px = 0.813em