9 Px to Rem – Easy Conversion Explained

9 px is equal to 0.5625 rem.

The conversion from pixels (px) to rem involves dividing the pixel value by the root font size, which by default is usually 16 pixels in browsers. So, 9 pixels divided by 16 gives 0.5625 rem. This unit helps with scalable and responsive design.

Conversion Tool

Conversion Formula

The formula to convert pixels to rem is:

rem = px ÷ root font size

The root font size is the base font size set in the HTML document, which is 16 pixels by default in most browsers. When you divide the pixel value by 16, you get the equivalent rem value. This means rem scales relative to the root font size.

For example, converting 9 px to rem:

• Start with 9 px.
• Divide 9 by 16 (the root font size).
• 9 ÷ 16 = 0.5625 rem.

This way, if the root font size changes, rem units adjust accordingly, making designs flexible.

Conversion Example

• 12 px to rem:
  • Take 12 px.
  • Divide 12 by 16.
  • 12 ÷ 16 = 0.75 rem.
  • So, 12 px equals 0.75 rem.
• 24 px to rem:
  • Start with 24 px.
  • Divide 24 by 16.
  • 24 ÷ 16 = 1.5 rem.
  • Therefore, 24 px equals 1.5 rem.
• 8 px to rem:
  • 8 px value.
  • Divide by 16.
  • 8 ÷ 16 = 0.5 rem.
  • Hence, 8 px is 0.5 rem.
• 32 px to rem:
  • Take 32 px.
  • Divide 32 by 16.
  • 32 ÷ 16 = 2 rem.
  • So, 32 px equals 2 rem.

Conversion Chart

The chart shows pixel values in the left column and their rem equivalents on the right. You can find the px value you want and see the rem value to use in your CSS for scalable sizing.

Related Conversion Questions

• How do I convert 9 px to rem for responsive design?
• What is the rem equivalent of 9 pixels with a 16px base?
• Can I use 9 px as rem value directly in CSS?
• How does changing root font size affect 9 px in rem?
• Is 9 px larger or smaller than 1 rem?
• How to calculate rem from 9 px if root font size is different?
• What happens if 9 px is converted to rem with 20px root size?

Conversion Definitions

px: A “px” or pixel is a fixed unit representing one dot on a digital screen. Pixels are absolute units in CSS, meaning they don’t change size based on user settings or device resolution, providing precise control over element dimensions and layout.

rem: The “rem” unit stands for “root em” and measures size relative to the root element’s font size in HTML. Unlike px, rem scales when the root font size changes, allowing flexible and accessible web design that adjusts across devices and user preferences.

Conversion FAQs

Why should I use rem instead of px for font sizes?

Using rem units makes your typography scalable and accessible. If a user changes browser default font size, rem-based sizes adjust accordingly, while px remains fixed, potentially causing readability issues. Rem units help maintain consistent proportions across different devices.

What if the browser’s root font size isn’t 16px, how does it affect 9 px to rem?

If the root font size changes, the rem value for 9 px changes too. To convert correctly, divide 9 by the current root font size. For example, if root is 20 px, then 9 ÷ 20 = 0.45 rem. Always confirm root font size before converting.

Can rem units be negative like pixels?

Yes, rem can be negative, just like px. Negative values in CSS are valid for properties that accept them, like margins or positioning, and convert by dividing the negative pixel value by root font size similarly.

How does rem conversion improve responsive design?

Rem units allow elements to resize relative to the root font size. When used instead of px, designs become more flexible: font sizes, paddings, and margins adapt when root size changes due to device or user settings, making layouts more consistent across devices.

Is there a difference between rem and em when converting from px?

Yes. Rem is relative to the root element’s font size, while em is relative to the font size of the current element. So, converting px to rem always uses root size, but px to em depends on the element’s inherited size, which can cause compounding effects.

Last Updated : 23 June, 2025

Sandeep Bhandari

Sandeep Bhandari holds a Bachelor of Engineering in Computers from Thapar University (2006). He has 20 years of experience in the technology field. He has a keen interest in various technical fields, including database systems, computer networks, and programming. You can read more about him on his bio page.