PX ↔ REM Converter

Convert between px and rem instantly. Adjust the root font size for your project and get a reference table of common values — all calculated live in your browser.

10px32px
px
px
rem
rem
Live Preview 16px

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Common Values
px rem

How to use

Step 1

Enter a value

Type a px value to get the rem equivalent, or type a rem value to get px back. Conversion is live on every keystroke.

Step 2

Adjust the base

If your project sets a custom root font size (e.g. 62.5% = 10px), change the base to match. Slider and number input stay in sync.

Step 3

Use the table

Scroll down to the reference table for quick lookups of the most commonly used sizes. Values recalculate automatically when the base changes.

Step 4

Copy the result

Click the Copy button next to any rem output to copy the value to your clipboard — ready to paste into your CSS.

FAQ

"Root em" — a CSS unit relative to the font size of the root <html> element. Browsers default to 16px, so 1rem = 16px out of the box.
rem scales with the user's browser font settings, making your UI more accessible. It also makes global font scaling easy — change one root value and everything adjusts proportionally.
Browsers default to 16px. However, many projects set html { font-size: 62.5%; } to make 1rem = 10px for easier mental math. Always check your project's CSS reset or global styles.
This tool focuses on px ↔ rem conversion only. For other unit conversions (em, vw, pt, etc.) keep an eye on our other tools at StackFreeks Tools.
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