PX to REM Converter
Your ultimate guide to scalable and responsive web typography.
What is the PX to REM Converter?
The PX to REM Converter is an online tool designed to help developers and designers convert pixel (px) values into rem units quickly and accurately. Instead of manually calculating values each time, this converter instantly provides accurate results based on your selected root font size.
This tool is especially useful when working on responsive layouts, scalable typography, and modern CSS frameworks. When you convert px to rem, your designs remain flexible and adapt consistently across different devices and user preferences.
How to Use PX to REM Converter?
Using the PX to REM Converter is simple and straightforward. You don’t need advanced CSS knowledge to get accurate results.
- Step 1: Enter the pixel (px) value you want to convert
- Step 2: Set the base (root) font size, default is usually 16px
- Step 3: The converter instantly shows the equivalent rem value
- Step 4: You can also reverse the process by entering a rem value to get px
32px ÷ 16 = 2rem
Instant results save you time and reduce the chances of manual calculation mistakes.
How to Convert PX to REM?
PX to REM conversion follows a simple mathematical formula based on the root element’s font size.
px = rem × root font-size
Example Conversion
Root font size: 16px
Pixel value: 24px
24 ÷ 16 = 1.5rem
If your root font size is different, the result will also change. That’s why this converter allows you to customize the base value.
PX to REM Conversion Table (Base: 16px)
| PX | REM | PX | REM |
|---|---|---|---|
| 10px | 0.625rem | 140px | 8.75rem |
| 20px | 1.25rem | 150px | 9.375rem |
| 30px | 1.875rem | 160px | 10rem |
| 40px | 2.5rem | 170px | 10.625rem |
| 50px | 3.125rem | 180px | 11.25rem |
| 60px | 3.75rem | 190px | 11.875rem |
| 70px | 4.375rem | 200px | 12.5rem |
| 80px | 5rem | 210px | 13.125rem |
| 90px | 5.625rem | 220px | 13.75rem |
| 100px | 6.25rem | 230px | 14.375rem |
| 110px | 6.875rem | 240px | 15rem |
| 120px | 7.5rem | 250px | 15.625rem |
| 130px | 8.125rem | - | - |
Why Convert PX to REM?
Choosing rem over px offers multiple benefits in today’s web development.
- Better responsiveness: Layouts scale smoothly across devices
- Accessibility: Users who increase browser font size get a better experience
- Consistency: All rem values depend on one root setting
- Easier maintenance: Change one value, update the entire layout
This is why rem is the preferred choice in modern CSS for font sizes, spacing, and layouts.
What is a Root Element?
The root element in HTML is the <html> tag. REM units are always calculated relative to the font size of the root element, not the parent element em.
If the root font size is adjusted, every rem value on the website scales automatically, which makes rem a highly flexible unit.
How to Add Font-Size to Root Element?
There are multiple ways to define font size for the root element in CSS.
Inline Style
This method applies styles directly in the HTML file.
Internal Stylesheet
html { font-size: 16px; }
</style>
External Stylesheet (Recommended)
The most professional and scalable approach.
How to Target the Root Element?
There are different CSS selectors you can use to target elements, including the root element.
CSS Element Selector
The most common and recommended method.
CSS ID Selector
Rarely used for the root element and generally not recommended.
CSS Class Selector
Used only in special cases where a class is applied.
PX vs REM – Key Differences
| Feature | PX | REM |
|---|---|---|
| Unit Type | Fixed | Relative |
| Responsive | ❌ No | ✅ Yes |
| Accessibility | ❌ Limited | ✅ Better |
| Maintenance | ❌ Hard | ✅ Easy |
| Root-Based | ❌ No | ✅ Yes |
Common Use Cases
- Converting design specs from Figma or XD
- Building responsive typography systems
- Creating scalable layouts
- Working with CSS frameworks
- Maintaining consistent spacing across pages
Final Summary
The PX to REM Converter is a simple but powerful tool for modern web development. It removes the need for manual calculations, improves accuracy, and helps developers create responsive, accessible designs with ease. By understanding how rem units work with the root element and applying the right font-size strategy, you can build scalable layouts that adjust naturally to different devices and user preferences.
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