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PX / REM Calculator

Convert pixel values to rem or em units and back, based on a configurable root font size.

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PX / REM Calculator
Result
1.5rem
Quick reference at 16px base
8px
0.5rem
12px
0.75rem
14px
0.875rem
16px
1rem
18px
1.125rem
20px
1.25rem
24px
1.5rem
32px
2rem
40px
2.5rem
48px
3rem
64px
4rem
What is PX / REM Calculator?

Convert pixel values to rem or em units and back, based on a configurable root font size.

How it works

SiteIndex divides or multiplies your pixel value by the root font size you set (16px by default) to convert between px, rem, and em units instantly.

Where a network request is required, SiteIndex validates public HTTP/HTTPS targets before making the request.

Common uses
  • Convert a design's pixel spacing into rem units for a CSS design system.
  • Check what a rem value equals in pixels at a custom base font size.
  • Build a quick reference table of common px-to-rem conversions.
Limitations
  • Results depend on the browser, network, input, and external service involved.
  • This tool is informational and does not replace specialist diagnostics or professional advice.
FAQ
What if my project uses a different base font size?
You can change the root font size used for the conversion; 16px is the common browser default.

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