Why Convert PX to REM?
In responsive web design, using REM units offers several advantages over pixels:
- Scalability: REM units are relative to the root font size (typically 16px), making it easy to scale entire designs by changing one value.
- Consistency: Unlike EM, which depends on the font size of the parent element, REM ensures that sizes are consistent across all elements of your design.
- Accessibility: REM units allow users to adjust font sizes in their browsers without breaking your design, making websites more user-friendly, especially for those with visual impairments.
What Are Pixels (PX)?
Pixels are the smallest unit of measurement on a screen. In web development, they are used to define the size of various elements, such as text, images, and layouts.
For example, if you set a font size to 16px, the text will be rendered 16 pixels tall on the screen.
The issue with using pixels exclusively is that they don’t scale well when dealing with different screen sizes or user settings. This is why developers often prefer REM for responsive designs.
What Are REM Units?
REM (Root EM) is a relative unit in CSS used for sizing elements. REM values are always relative to the root element of your webpage, which is typically the <html>
element. By default, the root element has a font size of 16px, so 1rem equals 16px.
For example:
- 1rem = 16px
- 2rem = 32px
- 0.5rem = 8px
If you change the base font size (let’s say from 16px to 20px), all elements sized with REM will adjust accordingly. This gives you a powerful way to ensure your design is responsive.
How to Convert PX to REM: The Formula
Converting PX to REM is quite simple. Here’s the formula:
REM = Pixels / Base Font Size
For example, if you have a button that’s 32px wide and the base font size is 16px, you would convert it like this:
REM = 32px / 16px = 2rem
This means that your button would now be 2rem wide. If you change the base font size later, the button will scale up or down automatically.
PX to REM Conversion Table
Here’s a quick table that shows some common conversions from pixels to REM based on a 16px base font size:
PX
|
REM
|
1px
|
0.0625rem
|
2px
|
0.125rem
|
3px
|
0.1875rem
|
4px
|
0.25rem
|
5px
|
0.3125rem
|
6px
|
0.375rem
|
8px
|
0.5rem
|
10px
|
0.625rem
|
12px
|
0.75rem
|
14px
|
0.875rem
|
15px
|
0.9375rem
|
16px
|
1rem
|
18px
|
1.125rem
|
20px
|
1.25rem
|
24px
|
1.5rem
|
25px
|
1.5625rem
|
28px
|
1.75rem
|
32px
|
2rem
|
36px
|
2.25rem
|
40px
|
2.5rem
|
44px
|
2.75rem
|
48px
|
3rem
|
50px
|
3.125rem
|
56px
|
3.5rem
|
64px
|
4rem
|
72px
|
4.5rem
|
75px
|
4.6875rem
|
80px
|
5rem
|
90px
|
5.625rem
|
100px
|
6.25rem
|