ToolSnippet
🎨Part of Design & CSS Generators

Bidirectional PX to REM & REM to PX Converter

Convert pixels to rem and rem to pixels instantly with custom root font size (16px / 10px) and standard Tailwind reference table.

About This Tool

PX to REM Converter helps developers convert pixel values into relative REM units for accessible, scalable web layouts, featuring customizable root font sizes and a full Tailwind CSS conversion reference table.

Key Features

Real-time bidirectional conversion (PX <-> REM)
Customizable root base font size (16px, 10px, or custom)
Interactive Tailwind CSS size reference table
One-click values loading

How to Use

  1. 1Enter a pixel value or a rem value in either input box.
  2. 2Choose your root font size (default 16px, or 10px 62.5% trick).
  3. 3Conversion updates bidirectionally in real time.
  4. 4Click any item in the reference table to load standard sizes.

Why Use ToolSnippet PX to REM & REM to PX Converter?

REM units respect user browser font size preferences for accessibility.
Bidirectional: calculate px from rem or rem from px instantly.
Includes complete conversion reference table matching Tailwind CSS spacing scales.

Tips for Best Results

  • Use REM for font sizes, margins, and padding, and PX for 1px borders
  • Standard browser default root font size is 16px (1rem = 16px)

Frequently Asked Questions

Why should I use REM instead of PX in CSS?

REM units scale proportionally when users change their default browser font size, improving web accessibility.

What is the 62.5% CSS font-size trick?

Setting 'html { font-size: 62.5%; }' makes 1rem equal to exactly 10px (e.g. 1.6rem = 16px), simplifying mental math.

Related Tools

All Design & CSS Generators →

Base64 to Image Decoder & Downloader

Convert Base64 data strings into viewable and downloadable PNG, JPEG, SVG, or WEBP images.

WCAG Color Contrast Checker

Check color contrast compliance for text and UI elements against WCAG 2.1 AA and AAA accessibility standards.

Color Shades & Tint Generator

Generate a full 50-950 Tailwind/CSS palette of tints and shades from any base color.