CSS Unit Converter helps you generate CSS and design code quickly and accurately, right in your browser. Whether you need to convert between css units: px, rem, em, pt, %, vw, vh, and more, this tool eliminatesmanual CSS tweaking, cross-browser inconsistencies, and design guesswork by giving you instant, reliable results. Every operation runs locally on your device — nothing is uploaded to any server, so your data stays completely private.
Key Features
All CSS Units
Convert between px, rem, em, pt, pc, in, cm, mm, q, vw, vh, vmin, vmax, %, ch, ex.
Base Size Control
Set custom root font-size (default 16px) for accurate rem/em conversions.
Viewport Context
Set viewport dimensions for accurate vw/vh/vmin/vmax conversions.
Real-Time Results
See all conversions update simultaneously as you type.
Common Use Cases
- Converting pixel designs to rem units for accessible, scalable typography
- Calculating viewport-based sizes for responsive layouts
- Translating design mockup units (px, pt) to production CSS units
CSS Unit Converter
Convert between CSS units: px, rem, em, pt, %, vw, vh, and more.
How to Use
Enter a value
Type a number in the value field. Conversion happens instantly as you type.
Select units
Choose the source and target units from the dropdown menus.
Swap units
Click the swap button to quickly reverse the from/to units.
Copy results
Click the copy button next to any result to copy the value with its unit.
| Unit | Value | |
|---|---|---|
| px | 16.0000 | |
| em | 1.0000 | |
| rem | 1.0000 | |
| % | 0.8333 | |
| vw | 0.8333 | |
| vh | 1.4815 | |
| vmin | 1.4815 | |
| vmax | 0.8333 | |
| cm | 0.4233 | |
| mm | 4.2334 | |
| in | 0.1667 | |
| pt | 12.0000 | |
| pc | 1.0000 | |
| ch | 2.0000 | |
| ex | 2.0000 |
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What is CSS Unit Converter?
CSS Unit Converter is a CSS design tool that convert between css units: px, rem, em, pt, %, vw, vh, and more. It includes All CSS Units, Base Size Control, Viewport Context to generate production-ready CSS code. All rendering happens locally, giving you real-time previews without any server round-trips.
Designing CSS visually often requires switching between an editor and a browser, tweaking values blindly until they look right. CSS Unit Converter bridges this gap by combining visual controls with live preview — you adjust parameters and see the result instantly. When you are satisfied, copy the generated CSS directly into your project. This workflow is particularly useful for prototyping UI components, generating consistent design tokens, and learning how CSS properties interact.
Frequently Asked Questions
How does the All CSS Units feature work?
The All CSS Units feature convert between px, rem, em, pt, pc, in, cm, mm, q, vw, vh, vmin, vmax, %, ch, ex. It is designed to be intuitive and responsive, giving you immediate feedback as you interact with the tool. All processing happens locally in your browser.
What is the benefit of base size control?
Base Size Control set custom root font-size (default 16px) for accurate rem/em conversions. This capability sets CSS Unit Converter apart from basic alternatives by providing more comprehensive functionality while maintaining the privacy and speed of local processing.
Is CSS Unit Converter really free to use?
Yes, CSS Unit Converter is completely free with no hidden charges, no sign-up requirements, and no usage limits. You can use it as often as you need, for any purpose — personal projects, commercial work, or educational use. There are no premium tiers or paid features.
Does CSS Unit Converter work on mobile devices?
Yes, it works on any device with a modern web browser — desktop, tablet, or phone. The interface is responsive and adapts to your screen size. Since all processing is done locally, you get the same performance regardless of your device.
What happens to my data when I use CSS Unit Converter?
Your data never leaves your device. Every operation is performed locally in your browser using JavaScript. No information is uploaded, stored, logged, or shared with any server. This privacy-first approach means you can work with sensitive data — passwords, API keys, personal information — without any risk of exposure.
Key Features
All CSS Units
Convert between px, rem, em, pt, pc, in, cm, mm, q, vw, vh, vmin, vmax, %, ch, ex.
Base Size Control
Set custom root font-size (default 16px) for accurate rem/em conversions.
Viewport Context
Set viewport dimensions for accurate vw/vh/vmin/vmax conversions.
Real-Time Results
See all conversions update simultaneously as you type.
Common Use Cases
CSS Unit Converter is useful in a variety of scenarios across different workflows:
Converting pixel designs to rem units for accessible, scalable typography
Calculating viewport-based sizes for responsive layouts
Translating design mockup units (px, pt) to production CSS units
Tips & Best Practices
Set your root font-size first
Accurate rem/em conversions depend on your base font size. The default is 16px, but adjust it to match your project's CSS root font-size setting.
Use rem for spacing, em for typography
rem units are relative to the root element and consistent everywhere — ideal for margins and padding. em units are relative to the parent and best for text-relative sizing.
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Generate harmonious color palettes with monochromatic, analogous, complementary, triadic, and tetradic schemes.
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