CSS Units Converter (px to rem)

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Convert CSS pixel values to rem units for scalable, accessible designs.

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About CSS Units Converter (px to rem)

Paste your CSS and have all pixel values automatically converted to rem equivalents. Rem units scale with the root font size, making layouts more accessible and easier to maintain. Configure the base font size (default 16px) to match your project's root font size.

How to use

  1. Paste your CSS containing px values into the input panel.
  2. Choose the base font size that matches your root element (default: 16px).
  3. The converted CSS with rem values appears instantly in the output panel.

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Frequently Asked Questions

FAQs about CSS Units Converter (px to rem)

What is a rem unit in CSS?

Rem (root em) is a CSS unit relative to the root element's font size. If the root font size is 16px, then 1rem equals 16px.

Why use rem instead of px?

Rem units respect the user's browser font-size preferences, making designs more accessible. They also make it easier to scale the entire layout by changing only the root font size.

What base font size should I choose?

Choose the font size set on your html element. Most browsers default to 16px, but some projects use 14px or 10px for easier mental arithmetic.

Does this change all px values including border widths?

Yes, all numeric px values in the CSS are converted. You may want to manually review border widths and shadow values that are commonly kept in px.

Is my data safe?

All conversion runs client-side in your browser. No data is sent to any server.