Rem to Px Converter

Free online tool to convert CSS unit REM values to pixels.

Test Your Web Or Mobile Apps On 3000+ Browsers
Signup for free...

Base size in px. Default







Reset Reset

CSS Style Properties


h1 {

font-size: 1em;



h1 {

font-size: 1rem;



h1 {

font-size: 16px;



h1 {

font-size: 100%;



h1 {

font-size: 12pt;


Unit Conversion Table (Base 16)


What is REM to Px Online Converter?

An REM to PX online converter is a web tool that simplifies the process of converting font sizes specified in REM units to pixels (PX). This conversion is crucial for responsive web design, as it ensures that text elements adjust smoothly to various screen sizes and resolutions. With this tool, web designers and developers can effortlessly maintain consistent typography and adaptability in their projects, enhancing the user experience and improving accessibility.

By using an REM to PX online converter, developers save time and effort when managing font sizes. This simplifies the maintenance of web designs and provides cross-browser compatibility, ensuring that text remains readable and visually appealing on different devices. These converters are valuable assets for achieving a cohesive and responsive web layout that caters to a diverse audience and evolving technology.

What is REM?

In CSS, “REM” stands for “root em.” It's a unit of measure that's relative to the size of the root element's font. Usually, the < html> element in your HTML document is the root element.

Unlike the “em” unit, which relates to the nearest parent's font size or the element's own font size, REM always refers to the actual font size of the element.

Let's say the root element is 16 pixels in size. 1 REM equals 16 pixels. For example, if a paragraph in your HTML document has a size that's 1.5 pixels, it'll be 24 pixels, which is 1.5 times your root font size.

The use of REM units in stylesheets allows you to define sizes more flexibly and consistently, as changes in the size of your root element will proportionally impact all of your REM based measurements across the entire document.

Because of this scalability, REM is especially useful for designing responsive designs, where elements can adapt to varying screen sizes and screen resolutions.

What is Px?

In CSS, “px” stands for “pixels”. It's a unit of measurement that's commonly used to describe the sizes of elements on web pages. Pixels are fixed-size units, meaning their value stays the same no matter what screen resolution you're looking at. When you specify dimensions in pixels, you're in control of the size of your elements, which makes it easier to create consistent layouts across devices.

It's also important to think about accessibility and user experience. Fixed pixel sizes can cause readability issues on different screen densities, or users may need to adjust the size of their text for better visibility. That's why designers often use relative units alongside pixels.

Pixels aren't always the most responsive choice when it comes to responsive web design. They don't adapt to different screen sizes, so designers often combine them with other units, such as percentage or viewport units to create more flexible layouts.

Using “p” in CSS is easy. For example, if you set a font size to “12px”, you'll see that the text will appear with a height equivalent

LambdaTest REM to PX Converter: A Versatile Solution for CSS Unit Conversions

LambdaTest's REM to PX Converter tool stands out as a vital utility for web designers and developers, offering a broad spectrum of CSS unit conversions. This multifaceted tool streamlines the conversion process of REM units into several formats, enhancing both responsive and accessible web design.

  • Pixel (PX) Conversion: Central to the tool's utility, the pixel conversion feature allows for precise control in designs, translating REM units into absolute pixel values – a staple in web layout and typography.
  • EM Conversion: The tool facilitates REM to EM conversions, aiding in creating scalable components and typography relative to parent element font sizes.
  • Percentage Conversion: Addressing fluid web design needs, the tool's percentage conversion feature is crucial for setting dimensions relative to parent elements, essential for responsive designs.
  • Point Conversion: The inclusion of point conversion adds versatility, especially useful when digital designs need to align with print standards.

Step-by-Step Guide on How to Use the REM to PX Converter Tool

The LambdaTest REM to PX Converter is a versatile tool designed for web designers and developers, facilitating the conversion of CSS units for responsive and consistent web design. Here's a more detailed guide on how to use it:

  • Access the Tool:
    • Visit the LambdaTest website.
    • Find the REM to PX Converter tool, specifically designed for web developers and designers.
  • Understand the Base Font-Size Concept:
    • The first step in using the tool is to set your base font-size. This is important because REM units are relative to this size.
    • In CSS, the base font-size is often set globally on the HTML element and serves as the foundation for scaling elements in REM units.
  • Input Your REM Value:
    • After setting your base size, input the REM value you wish to convert.
    • Put it in "REM" slot.
    • Click on "Convert" button for conversion.
  • Comprehensive Conversion Options:
  • The tool can convert REM values not just into pixels (PX), but also into other CSS units:

    • EM Conversion: Calculates how the REM value translates to EM based on the base font-size.
    • Percentage Conversion: Converts REM values into percentages, aiding in the creation of responsive designs that adapt to the parent element's size.
    • Point Conversion: Provides the equivalent value in points for completeness.
  • Get results and copy
    • You'll see the results in "CSS Style Properties" section.
    • You can copy and use the converted value.

Test How The REM to PX Converter Tool Works

Example Scenario:

Suppose you are working on a web design project and you have set the base font-size of your HTML document to 16px (which is often the default in browsers). You want to convert a font size specified in REM to pixels (PX) for a specific element.

Steps to Test the Converter:

  • Determine Your REM Value:
    • Let's say you want to convert a font size of 1.5rem.
    • This is a common size for slightly larger text, such as subheadings.
  • Set the Base Font-Size in the Tool:
    • Since your HTML document's base font-size is 16px, set this as the base size in the converter tool.
  • Input the REM Value:
    • Enter 1.5rem in the REM input field of the tool.
  • Perform the Conversion:
    • The tool will automatically calculate the equivalent size in pixels.
    • Given the base size of 16px, 1.5rem should be converted to 24px (since 1.5 x 16 = 24).
  • Review the Result:
    • The tool will display 24px as the output.
    • You can then use this pixel value in your CSS stylesheet if you need a fixed pixel size.
  • Copy and Use the Converted Value:
    • Copy the converted value.
    • Paste it into your CSS stylesheet, for example: font-size: 24px;.

This example demonstrates how you can use the REM to PX Converter tool to translate relative font sizes (REM) into absolute pixel units (PX), which can be particularly useful for ensuring consistency in designs where fixed sizes are required.

What Can You Do with the REM to PX Converter Tool?

The REM to PX Converter Tool is a valuable resource for web designers and developers seeking to create responsive and user-friendly websites. This tool simplifies the conversion of font sizes and other CSS properties from REM units to pixels (PX), enabling seamless typography scaling and enhancing cross-browser compatibility. Let's see why we need to use the REM to PX Converter

  • Responsive Typography: Convert REM units to PX to make your typography responsive to different screen sizes and resolutions.
  • Consistency: Ensure a consistent design by converting all units to one standard (either REM or PX) throughout your project.
  • Accessibility: Make your website more accessible by allowing users to adjust font sizes according to their preferences.
  • Easier Maintenance: Simplify code maintenance by using a single unit of measurement for fonts, making it easier to manage and update your design.
  • Cross-browser Compatibility: Address cross-browser compatibility issues by converting units to pixels, which is a universally supported unit of measurement.

Difference Between REM, PX and EM

DefinitionRoot EM. A flexible unit that is relative to the root element's (usually the HTML element) font size.Pixels. An absolute unit that corresponds to the actual number of pixels on a screen.A flexible unit relative to the font size of its own element (parent element's font size if not specified).
Responsive DesignHighly effective for responsive designs as it scales with the root element's font size, providing consistency across various devices.Less adaptable for responsive designs due to its fixed size, which doesn't change with screen or font size.Good for responsive design within a component as it scales with the parent element's font size, but can be inconsistent across different components.
Use CaseBest used for overall consistent sizing across a webpage, like global font sizes, layout spacing.Preferred for designs where precise, fixed sizing is needed, like images or fixed-layout components.Suitable for scalable components within a container, like buttons or modals that adapt to their container's font size.
ScalabilityUniformly scales with the root font size, making it easier to maintain relative sizing and accessibility.Non-scalable by nature. Requires additional CSS media queries for different screen sizes.Scales in relation to the parent element's font size, allowing for component-based scalability but can lead to complexity in nested structures.
Changing Base Size ImpactAdjusting the root font size will proportionally affect all elements styled in REM, offering an easy way to scale the entire UI.Changing the base size has no impact on elements sized in pixels, leading to a static layout regardless of root size changes.Adjusting the parent element's font size will directly affect elements styled in EM, potentially leading to varied outcomes across the UI.
AccessibilityEnhances accessibility as users can adjust the root font size for their needs, and the UI will adapt accordingly.Limited in terms of accessibility, as elements sized in pixels won't adapt to user's browser or system settings.Can be accessible but requires careful design to ensure that changes in parent font size don't adversely affect the layout.

Frequently Asked Questions

  • Why should I use REM for font sizes in my design?
  • REM units allow your typography to be responsive and adapt to various screen sizes, ensuring legibility and a better user experience.

  • When should I use PX units instead of REM?
  • PX units are suitable for elements that need to maintain a fixed size regardless of screen size, such as graphical elements or borders.

  • Do all browsers support REM units?
  • Yes, all modern browsers support REM units, making them a safe choice for web development.

  • Is it possible to mix REM and PX units in a design?
  • Yes, you can use a combination of REM and PX units, but it's important to maintain consistency within your design for a responsive and coherent look.

  • Is it necessary to convert REM to PX for every project?
  • The need to convert REM to PX depends on your project's specific requirements. If your design demands fixed font sizes, conversion may not be necessary. However, for responsive design, it's recommended for better scalability.

Did you find this page helpful?



More Tools

JSON PrettifyJSON MinifyHTML PrettifyHTML MinifyJavascript MinifyCSS MinifyCSS PrettifyXML MinifyXML PrettifyJavaScript ObfuscatorYAML Formatter & BeautifierSQL Formatter & BeautifierSQL MinifyJavaScript Formatter & BeautifierLua BeautifierPHP Formatter & Beautifier OnlinePython Formatter & Beautifier OnlineRandom JSON GeneratorRandom XML GeneratorRandom CSV GeneratorRandom YAML GeneratorPlaceholder Image GeneratorRandom Binary GeneratorRandom Character GeneratorRandom Color GeneratorRandom Date GeneratorRandom Decimal Fraction GeneratorRandom Decimal GeneratorRandom GUID GeneratorRandom Hex GeneratorRandom Octal GeneratorRandom IP GeneratorRandom MAC GeneratorRandom Number GeneratorRandom Paragraph GeneratorRandom Password GeneratorRandom Time GeneratorRandom UUID GeneratorRandom Sentence GeneratorRandom String GeneratorRandom Word GeneratorRandom Text from RegExTest Data GeneratorLorem Ipsum GeneratorCredit Card Number GeneratorQR Code GeneratorRandom Byte GeneratorRandom User name GeneratorRandom Unicode GeneratorRandom Base64 GeneratorRandom ISBN GeneratorBarcode GeneratorRandom name GeneratorRandom Address GeneratorRandom TSV GeneratorRandom Bitmap GeneratorRandom UTF8 GeneratorHash CalculatorHash Mac GeneratorCRC32 Hash CalculatorCRC32B Hash CalculatorRIPEMD128 Hash CalculatorRIPEMD160 Hash CalculatorRIPEMD256 Hash CalculatorRIPEMD320 Hash CalculatorMD2 Hash CalculatorMD4 Hash CalculatorADLER32 Hash CalculatorGost Hash CalculatorWhirlpool Hash CalculatorMD5 Hash CalculatorSHA1 Hash CalculatorSHA256 Hash CalculatorSHA384 Hash CalculatorSHA512 Hash CalculatorNTLM Hash GeneratorShake 256 Hash GeneratorFind And Replace StringHTML EscapeHtml UnescapeDifference Checker (String)Shuffle LettersShuffle Text LinesSorting ListString Split By DelimiterText LowercaseText UppercaseText RepeaterText RotaterDecimal To RomanCharacter CountWord CountLine CounterSentence CountURL ParseJSON EscapeJSON UnescapeExtract Text From HTMLExtract Text from JSONExtract Text from XMLStrip HTMLJSON ValidatorHTML Validator XML ValidatorYAML ValidatorCSS ValidatorXML EscapeCSV ValidatorJavaScript Validator & LinterJavaScript Escape

Try LambdaTest Now !!

Get 100 minutes of automation test minutes FREE!!

Next-Gen App & Browser Testing Cloud