Developer ToolsUpdated
CSS Unit Converter
Convert between CSS units (px, rem, em, %) online for free. Calculate responsive typography and layout values instantly.
Converted to rem
1.000rem
Converted to em
1.000em
Converted to %
1.33%
1rem = ? px
16.0px
Features
Handles large code files and data structures efficiently
Syntax-aware processing for accurate results
Copy, download, or export results in multiple formats
Works offline — no server round-trips needed
How to Use CSS Unit Converter
1
Open the Tool
Navigate to the CSS Unit Converter page to get started.
2
Provide Input
Upload your file, paste your content, or enter your data into the tool.
3
Configure Options
Adjust any available settings to customize the output to your needs.
4
Get Results
Process your data and download, copy, or save the result instantly.
Frequently Asked Questions
What is the default base font size?▼
The default base font size is 16px (browser default). You can customize it to match your design system.
How do you calculate percentage from pixels?▼
Percentage is calculated as (px / container width) × 100. Enter your container width to get accurate percentage values.