Web designers often use em and px to define font sizes and spacing. The em unit is relative to the parent element’s font size, while px represents a fixed pixel size. This article explains the relationship between the two and how to convert em to pixels.
The relationship between em and pixels
When you’re working on the text size of a website, you’ll often encounter two measurement units: em and pixels (px). Here’s how they relate to each other.
How em units work
An em is relative to the font size of the element’s parent. So, if you change the parent’s font size, that change also affects the size of elements that use the em unit.
For instance, if the font size of the parent element is 16 pixels, then 1 em equals 16 pixels.
To convert from em to pixels, you can use this formula: pixels = em multiplied by the parent font size.
The importance of parent font size
The font size of the parent element is the foundation for em calculations. So, to make accurate conversions, you have to know the parent font size.
Converting em to px: Methods and Tools
So, how do you actually convert from em to pixels?
Manual Conversion
The manual way involves a little detective work and some basic math:
- First, find out the font size of the parent element, expressed in pixels.
- Then, multiply the em value by that parent font size. For instance, if you have 1.5em and the parent font size is 16px, then 1.5em = 24px.
Using an em to px Converter
If math isn’t your thing, there are plenty of online tools that can do the conversion for you. Just plug in the parent font size and the em value, and poof, you’ve got your pixel equivalent!
Conversion Table
Here’s a handy-dandy conversion table for quick reference, assuming a default font size of 16px:
- 1em = 16px
- 2em = 32px
- 0.5em = 8px
- And so on…
Summary
When you’re coding a website, remember that em is a relative unit, and px (pixels) are absolute. You can convert em to pixels using manual calculations or online converters. But for accurate conversions, always consider the parent element’s font size.
If you’re interested in responsive web design, explore other CSS units, too!