PX to REM Converter
Convert Pixels (px) to REM units instantly for responsive CSS web design. Free online calculator.
Base Font Size (px)
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Quick Reference Table (Base: 16px)
Why use REM instead of PX?
REM (Root EM) is a scalable unit in CSS. Unlike pixels, which are absolute, REM units are relative to the root font size of the HTML document (default is 16px). This px to rem converter uses the formula rem = px ÷ root font size — the same calculation the tool above performs live as you type. Using REM units makes your websites more accessible, as they scale naturally when a user changes their browser's default font size.
How to Use It
Enter a pixel value (and optionally a custom root font size) and the equivalent rem value is calculated instantly — or work backwards by entering a rem value to see the equivalent pixels.
Example: Common px to rem Conversions
Assuming the standard 16px root font size, here are worked examples for frequently searched pixel values:
14px ÷ 16 = 0.875rem
16px ÷ 16 = 1rem
18px ÷ 16 = 1.125rem
20px ÷ 16 = 1.25rem
24px ÷ 16 = 1.5rem
32px ÷ 16 = 2rem
38px ÷ 16 = 2.375rem
120px ÷ 16 = 7.5rem
In other words: 16px in rem is 1rem, 18px to rem is 1.125rem, 20px in rem is 1.25rem, 24px to rem is 1.5rem, 38px to rem is 2.375rem, and 120 px to rem is 7.5rem — all at the default 16px root font size. If your project sets a different base font size, use the slider above to recalculate every value instantly.
Common Use Cases
- Converting fixed-pixel Figma or design specs into responsive CSS rem values.
- Auditing a stylesheet for accessibility by replacing px with rem.
- Looking up a specific conversion like 16px in rem or 120 px to rem without doing the division yourself.
- Converting a whole design system's spacing or type scale from px to rem in one pass.
FAQs
What is 16px in rem?
16px equals 1rem, assuming the default 16px root font size — since rem = px ÷ root font size, and 16 ÷ 16 = 1.
How do I convert px to rem?
Divide the pixel value by the root font size (16px by default, unless your project sets a different base). The formula is: rem = px ÷ root font size. For example, 24px ÷ 16px = 1.5rem.
What is 120px in rem?
120px equals 7.5rem at the standard 16px root font size (120 ÷ 16 = 7.5).
What is 18px to rem, and other common sizes?
At the default 16px root font size: 12px = 0.75rem, 14px = 0.875rem, 16px = 1rem, 18px = 1.125rem, 20px = 1.25rem, 24px = 1.5rem, 32px = 2rem, and 38px = 2.375rem.
What if the root font size isn't 16px?
Enter your custom root font size in the tool and every conversion — including the quick reference table — will adjust accordingly, using rem = px ÷ your custom base.