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Free PX to REM Converter | Katalon Online Tools

Written by Vincent N. | Dec 15, 2025 7:40:38 AM

EM

Pixel REM Percent Point
0.0625em 1px 0.0625rem 6.25% 0.75pt
0.125em 2px 0.125rem 12.5% 1.5pt
0.1875em 3px 0.1875rem 18.75% 2.25pt
0.25em 4px 0.25rem 25% 3pt
0.3125em 5px 0.3125rem 31.25% 3.75pt
0.375em 6px 0.375rem 37.5% 4.5pt
0.4375em 7px 0.4375rem 43.75% 5.25pt
0.5em 8px 0.5rem 50% 6pt
0.5625em 9px 0.5625rem 56.25% 6.75pt
0.625em 10px 0.625rem 62.5% 7.5pt
0.6875em 11px 0.6875rem 68.75% 8.25pt
0.75em 12px 0.75rem 75% 9pt
0.8125em 13px 0.8125rem 81.25% 9.75pt
0.875em 14px 0.875rem 87.5% 10.50pt
0.9375em 15px 0.9375rem 93.75% 11.25pt
1em 16px 1rem 100% 12pt
1.0625em 17px 1.0625rem 106.25% 12.75pt
1.125em 18px 1.125rem 112.5% 13.5pt
1.1875em 19px 1.1875rem 118.75% 14.25pt
1.25em 20px 1.25rem 125% 15pt
1.3125em 21px 1.3125rem 131.25% 15.75pt
1.375em 22px 1.375rem 137.5% 16.50pt
1.4375em 23px 1.4375rem 143.75% 17.25pt
1.5em 24px 1.5rem 150% 18pt
1.5625em 25px 1.5625rem 156.25% 18.75pt
1.625em 26px 1.625rem 162.5% 19.5pt
1.6875em 27px 1.6875rem 168.75% 20.25pt
1.75em 28px 1.75rem 175% 21pt
1.8125em 29px 1.8125rem 181.25% 21.75pt
1.875em 30px 1.875rem 187.5% 22.5pt
1.9375em 31px 1.9375rem 193.75% 23.25pt
2em 32px 2rem 200% 24pt
2.0625em 33px 2.0625rem 206.25% 24.75pt
2.125em 34px 2.125rem 212.5% 25.5pt
2.1875em 35px 2.1875rem 218.75% 26.25pt
2.25em 36px 2.25rem 225% 27pt
2.3125em 37px 2.3125rem 231.25% 27.75pt
2.375em 38px 2.375rem 237.5% 28.5pt
2.4375em 39px 2.4375rem 243.75% 29.25pt
2.5em 40px 2.5rem 250% 30pt
2.5625em 41px 2.5625rem 256.25% 30.75pt
2.625em 42px 2.625rem 262.5% 31.5pt
2.6875em 43px 2.6875rem 268.75% 32.25pt
2.75em 44px 2.75rem 275% 33pt
2.8125em 45px 2.8125rem 281.25% 33.75pt
2.875em 46px 2.875rem 287.5% 34.5pt
2.9375em 47px 2.9375rem 293.75% 35.25pt
3em 48px 3rem 300% 36pt
3.0625em 49px 3.0625rem 306.25% 36.75pt
3.125em 50px 3.125rem 312.5% 37.5pt

What is a PX to REM Converter?

A PX to REM converter is a specialized tool used by web developers and designers to convert pixel (px) values into root em (rem) units.

These conversions play a crucial role in creating responsive, scalable, and accessible web designs. Instead of relying on fixed units like pixels, REM units scale proportionally based on the root font size (typically defined on the <html> element).

This means that when a user adjusts their default font settings or accesses a site on a different device, elements defined with REM units will scale accordingly.

PX values are absolute, while REM values are relative. This relativity gives designers more flexibility and control over how layouts and typography adapt across screen sizes and user settings. By using a PX to REM converter, you can ensure your website maintains visual consistency and accessibility, no matter the viewing context.

What Can You Do with a PX to REM Converter Tool?

  • Convert Fixed Pixels to Scalable REM Units: Seamlessly convert pixel values (e.g.,20px) into equivalent REM values based on a given root font size (e.g., 1.25rem  if root is 16px).

  • Improve Typography Scalability: Use REM units for fonts, margins, paddings, and spacing to ensure consistent scaling across devices.

  • Support Accessibility Best Practices: Allow users with custom font size preferences to experience your site comfortably, as REM units scale with their browser settings.

  • Create Design Consistency: In large projects, REM ensures all sizes scale together. Changing the root font size instantly affects all REM-based elements, making global updates easy.

  • Ensure Cross-Platform Compatibility: Online PX to REM converters work across operating systems (Windows, macOS, Linux) and browsers (Chrome, Firefox, Safari, Edge), offering maximum accessibility.

How to use a PX to REM converter?

  1. Identify Your Root Font Size: Usually this is 16px unless overridden in your CSS.

  2. Gather the PX Values: Choose the fixed pixel values you'd like to convert (font-size, padding, margin, etc.).

  3. Input Values Into Converter: Use an online tool or calculator. Enter your pixel value and root font size.

  4. Retrieve the REM Output: The tool will display the exact REM value (e.g., 24px = 1.5rem with a 16px root).

  5. Update Your CSS: Replace px units in your stylesheet with the corresponding rem values.

  6. Test Across Browsers: Confirm that elements scale correctly across different environments.

Why Use REM Instead of PX?

  • PX (Pixels): A fixed, absolute unit. 16px always means 16 device pixels. It does not scale with user settings.

  • REM (Root EM): A relative unit that scales based on the root font size. 1rem = root size. It adapts to user preferences and device defaults.

For example:

  • If the root font size is 16px, then 1rem = 16px and 2rem = 32px

  • If the user increases their base font size to 20px, the same 2rem now becomes 40px.

Conclusion: REM supports responsive design and user accessibility; PX supports precision. Use REM for typography and layout; use PX for fine-tuned UI elements like icons.

Benefits of Using a PX to REM Converter

  • Simplifies Conversion: No need to manually divide every pixel value; just enter and get the result.

  • Ensures Design Scalability: Helps adapt designs to screen sizes, resolutions, and accessibility preferences.

  • Boosts Consistency: Changes made to the root font size will ripple through all REM-defined elements.

  • Saves Development Time: Avoid rewriting values in case of typography or layout revisions.

  • Enhances UX and Readability: Ensures users can read content comfortably on any device.

  • Responsive Typography: Makes it easier to implement scalable headings, paragraphs, and component spacing.

  • Cross-Browser Friendly: REM values behave consistently across all modern browsers.

Frequently Asked Questions

Which is better, PX or REM?
Use REM when accessibility and responsiveness matter. Use PX for fixed elements needing precision.

How big is 1rem in PX?
It depends on the root font size. By default, 1rem = 16px.

What is 20px in rem?
Assuming a root font size of 16px, 20px = 1.25rem (20 / 16 = 1.25).

Is 16px equal to 1rem?
Yes, if the root font size is 16px. However, if the root font size is changed, 1rem will equal the new root value.