PX to REM Converter
Convert a pixel value to rem for CSS that scales properly with user font-size preferences.
Browsers default to a 16px root font size unless overridden by the page's CSS or the user's browser settings — adjust it above if your project uses a different base.
Processing happens locally in your browser. Nothing you enter is uploaded.
How It Works
Enter a pixel value and the root font size (16px unless your project overrides it). The rem equivalent updates instantly.
rem = px ÷ root font size (16px by default)
Example
16px is 1rem, and 24px is 1.5rem, at the default 16px root font size.
Frequently Asked Questions
- Why use rem instead of px in CSS?
- rem units scale with the user's font-size preference (including browser zoom and accessibility settings), while px stays fixed — rem is generally preferred for font sizes and spacing for this reason.
- What if my project changes the root font size?
- Some projects set the html element to something other than the browser default of 16px (for example, 62.5% to make 1rem = 10px) — adjust the root font size field to match your project's actual value.
Related Tools
REM to PX Converter
Convert rem units to pixel values, with a configurable root font size.
CSS clamp() Calculator
Generate a fluid CSS clamp() value that scales between a minimum and maximum size across viewport widths.
Base64 Encoder / Decoder
Encode text to Base64, or decode Base64 back to plain text.
Color Converter
Convert between HEX and RGB color formats.
Hash Generator
Generate a SHA-1, SHA-256, or SHA-512 hash of any text.
HTML Encoder / Decoder
Encode text to HTML entities, or decode HTML entities back to plain text.