CSS unit converter. Convert between px, rem, em, vw, vh, %, pt, and more with base size and viewport control. Real-time results.
100% browser-based — your data never leaves your device
Convert between CSS units: px, rem, em, pt, %, vw, vh, and more.
Type a number in the value field. Conversion happens instantly as you type.
Choose the source and target units from the dropdown menus.
Click the swap button to quickly reverse the from/to units.
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 |
Generate harmonious color palettes with monochromatic, analogous, complementary, triadic, and tetradic schemes.
Border Radius GeneratorGenerate CSS border-radius values with a visual preview. Create smooth corners and custom shapes for your elements.
Box Shadow GeneratorCreate custom CSS box-shadow effects with a visual editor.
CSS Gradient GeneratorCreate linear and radial CSS gradients with a visual editor.
CSS Unit ConverterConvert between CSS units: px, rem, em, pt, %, vw, vh, and more.
CSS Grid GeneratorCreate CSS grid layouts visually with customizable columns, rows, and gaps.
Flexbox GeneratorCreate flexbox layouts visually with alignment, direction, and wrapping controls.
Bezier GeneratorCreate and preview CSS cubic-bezier easing curves for animations and transitions.
CSS Unit Converter is a free online design tool that convert between css units: px, rem, em, pt, %, vw, vh, and more. It works entirely in your browser — no downloads, no installations, and no server uploads required. UI/UX designers, frontend developers, marketing teams use CSS Unit Converter when they need a fast, privacy-respecting way to process design data without installing additional software. It supports capabilities such as all css units, base size control, viewport context. Additional features include real-time results. Common use cases include 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. All processing happens locally using modern browser APIs, which means your data never leaves your device. This makes CSS Unit Converter ideal for working with sensitive data, proprietary code, or any situation where privacy matters.
CSS Unit Converter is a free online design tool that helps you convert between css units: px, rem, em, pt, %, vw, vh, and more. Key capabilities include all css units, base size control, viewport context. All processing is done locally in your browser — no data is uploaded, stored, or shared with any server. There are no sign-ups, no file size limits, and no hidden charges. It is commonly used to converting pixel designs to rem units for accessible, scalable typography.
Type the numeric value you want to convert in the input field.
Choose the unit you're converting from (e.g., px) and the unit you want to convert to (e.g., rem).
Set your project's root font-size for rem/em accuracy, or viewport dimensions for vw/vh conversions.
| Category | Details |
|---|---|
| Input Limits | Maximum output complexity: Browser memory bound |
| Color precision: 32-bit RGBA (16.7M colors + alpha) | |
| Supported Formats | CSS, SCSS variables, Hex / RGB / HSL / OKLCH color formats |
| Browser Engine |
|
All operations run entirely in your browser using built-in Design APIs. No server uploads, no data storage, and no third-party requests.
CSS Unit Converter is ideal when you need to converting pixel designs to rem units for accessible, scalable typography without installing software or uploading data to a server. Since everything runs in your browser, there is no setup time and no risk of your data being stored on external servers. For one-off tasks and quick processing, CSS Unit Converter is faster than setting up a local development environment or using a command-line tool.
No. CSS Unit Converter processes everything entirely in your browser using JavaScript. Nothing you type, paste, or upload is ever transmitted to any server. Your data never leaves your device.
rem is relative to the root element's font-size (usually 16px on browsers), while em is relative to the parent element's font-size. This makes rem more predictable for global spacing.
Enter your px value and select vw as the target unit. Set the viewport width to match your design breakpoint (default 1920px). The tool computes the equivalent vw value.
Convert between px, rem, em, pt, pc, in, cm, mm, q, vw, vh, vmin, vmax, %, ch, ex.
Set custom root font-size (default 16px) for accurate rem/em conversions.
Set viewport dimensions for accurate vw/vh/vmin/vmax conversions.
See all conversions update simultaneously as you type.
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
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.
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.
Explore more tools in the Design workspace:
Color Palette Generator
Generate harmonious color palettes with monochromatic, analogous, complementary, triadic, and tetradic schemes.
Border Radius Generator
Generate CSS border-radius values with a visual preview. Create smooth corners and custom shapes for your elements.
Box Shadow Generator
Create custom CSS box-shadow effects with a visual editor.
CSS Gradient Generator
Create linear and radial CSS gradients with a visual editor.
CSS Grid Generator
Create CSS grid layouts visually with customizable columns, rows, and gaps.
Flexbox Generator
Create flexbox layouts visually with alignment, direction, and wrapping controls.