Pixel to REM
Convert pixel (px) values to rem units easily with this tool. Customize root font size, get real-time results, and improve responsive design workflows.
Pixel to REM Converter
Converted Result:
About Pixel to REM Converter
Our free Pixel to REM Converter is an essential utility for web developers and UI designers who build responsive, accessible websites. REM (root em) is a relative CSS unit that scales based on the root font size, making it ideal for creating flexible layouts that adapt to user preferences and device sizes. This tool eliminates the need for manual calculations, letting you instantly convert between pixels and REM values.
Why Use REM Instead of Pixels? While pixels are fixed units, REM units are relative to the root font size (typically 16px in browsers). This means your entire design scales proportionally when users adjust their browser's font size settings, improving accessibility. REM also simplifies responsive design—change the root font size, and all REM-based elements scale automatically. Modern CSS frameworks and accessibility guidelines recommend REM over fixed pixels.
- Bi-directional conversion: enter PX to get REM, or REM to get PX.
- Customizable root font size for project-specific calculations.
- Real-time conversion as you type for instant feedback.
- One-click copy for quick pasting into your CSS.
- Supports decimal precision for accurate conversions.
Whether you're converting a design mockup from pixels to REM, debugging responsive layouts, or ensuring your site meets accessibility standards, this calculator provides accurate, instant conversions. Simply enter your value, adjust the root font size if needed, and copy the result.
How to Use
Converting between pixels and REM is simple:
- Set the root font size (default is 16px, which is the browser standard).
- Enter your pixel value to calculate the equivalent REM value.
- Or enter a REM value to calculate the equivalent pixel value.
- Results update automatically as you type.
- Click "Copy Result" to copy the conversion to your clipboard.
- Use "Clear" to reset and start a new conversion.
Frequently Asked Questions
What is the difference between PX and REM?
PX (pixels) are absolute, fixed units—16px is always 16px regardless of context. REM is relative to the root font size, so 1rem equals the root font size (usually 16px). If the root changes to 20px, 1rem becomes 20px. This makes REM more flexible for responsive and accessible design.
What is the standard root font size?
The default root font size in all modern browsers is 16px. This means 1rem = 16px by default. However, developers often set a different root size (e.g., 10px for easier math) or let users adjust it for accessibility. This converter lets you specify any root size for accurate calculations.
What's the formula for conversion?
- PX to REM: rem = px ÷ rootFontSize (e.g., 32px ÷ 16 = 2rem)
- REM to PX: px = rem × rootFontSize (e.g., 2rem × 16 = 32px)
When should I use REM vs. pixels?
- Use REM for: font sizes, spacing, margins, padding, and layout dimensions that should scale.
- Use PX for: borders, specific design elements that shouldn't scale, or when exact pixel control is needed.
- Accessibility: REM is preferred for text and spacing to respect user font size preferences.
How does REM help with responsive design?
When you use REM units throughout your CSS, you can change the entire scale of your website by adjusting just one value: the root font size. This is commonly done in media queries—smaller root size for mobile, larger for desktop. All REM-based elements scale proportionally, creating responsive layouts with minimal code.
Why is REM better for accessibility?
Many users adjust their browser's default font size for better readability (especially those with visual impairments). When you use REM, your entire layout scales to match their preference. Fixed pixels ignore this setting, potentially making your site unusable for some users. REM ensures your design respects user needs.
Recently Used
No recent tools
Related Tools
Features
- 100% Free
- No registration required
- Fast processing
- Secure & private