About EM to PX
CSS length units are either absolute, like px and pt, or relative, like rem, em, percent, and vw. This converter first turns your value into pixels, then into every other unit. Rem and em use the base font size (16px by default), pt uses the fixed ratio of 72pt to 96px, percent is taken relative to the base font size, and vw relative to the viewport width you enter. Results are rounded to four decimals.
How to use EM to PX
- Fill in "Value", "From unit", "Base font size" and "Viewport width".
- The result appears below and updates as you type.
- Copy the result with the copy button, or download it as a file where that is offered.
Questions about EM to PX
What is the difference between rem and em?
The rem unit is relative to the font size of the root html element, so it is the same everywhere on the page. The em unit is relative to the font size of the current element, so it compounds when elements are nested.
Why use rem instead of px for font sizes?
Values in rem scale with the font size the user has set in the browser, while px values stay fixed. Sizing text in rem respects that preference, which helps people who need larger text.
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