PX to REM Converter

Design Tools

Convert pixels to rem and em for CSS

FreePrivateInstant
Convert
Value
Root font size (px)
Full guide, 3 min readpx vs rem: why your font sizes should be allowed to scaleRead the story behind this tool →
Embed this tool on your websiteFree
  1. Choose how tall the frame should be.
  2. Press Copy code.
  3. Paste it into your page, blog, WordPress or Notion HTML block.
Height
Live previewAll embeddable tools

The tool runs inside your visitor's browser, nothing is uploaded, and a small "Powered by ToolCloak" line stays under it. The second line (script) is optional: it makes the frame fit the tool's height.

Similar tools you may like

Color ConverterConvert HEX / RGB / HSL / HSV
CSS Clamp() GeneratorFluid responsive font sizes with clamp()
Shoe Size ConverterUS, UK, EU and cm shoe sizes
Angle ConverterConvert degrees, radians and gradians
Area ConverterConvert sq ft, sq m, acres and hectares
ASCII & Unicode ConverterText ↔ character codes (dec, hex, binary)

History

All history →

PX to REM Converter — at a glance

Convert pixel sizes to rem and em units (or back) based on your root font size.

Your values
24px at 16px root
Run
Result
1.5rem

How to use it — step by step

A pixel or rem value and your root font size.

1

Enter your values

Fill in the boxes. Sample values are already there so you can see how it works.

2

Calculate

Press the button to get your answer instantly.

3

Read the result

The main answer is shown in a large card with extra details below it.

4

Copy it

Use the copy button to save the result anywhere.

Pro tips

Small things that make the result better.

✦Browsers use 16px as the default root size.
✦rem units respect the user’s font-size setting.
✦em depends on the parent element’s size, rem on the root.

Quick facts

Freeno signup, no limit
Instantresult in a moment
Privatenothing is uploaded
Any devicephone, tablet or PC

Frequently Asked Questions

Why use rem instead of px?+

rem scales with the user’s browser font settings, which is better for accessibility.

Is my data safe?+

Yes. Everything runs inside your own browser. Your text, files and images are never uploaded to any server.

Is this tool really free?+

Yes — completely free, no signup, no watermark and no usage limit.

More Free Tools

Guides you might like

All guides →
Color ConverterHEX, RGB and HSL: three ways to write the same colour, and which to use
Aspect Ratio Calculator16:9, 4:3, 1:1: aspect ratios without cropping surprises
Color Contrast CheckerIs your text readable? The contrast ratio, explained
Pythagorean Theorem CalculatorPythagorean theorem: the 3-4-5 trick, ladders, TV sizes and how to check a right angle