Easily convert REM to PX with our online REM to PX Converter. Perfect for web designers and developers looking to ensure responsive and accessible designs.
REM to Pixels (PX)
We’re assuming the standard default browser font-size of 16px
| REM | Pixels |
| 0.01rem | 0.16px |
| 0.03rem | 0.48px |
| 0.05rem | 0.8px |
| 0.08rem | 1.28px |
| 0.1rem | 1.6px |
| 0.15rem | 2.4px |
| 0.2rem | 3.2px |
| 0.5rem | 8px |
| 1rem | 16px |
| 2rem | 32px |
| 3rem | 48px |
| 4rem | 64px |
| 5rem | 80px |
| 6rem | 96px |
| 8rem | 128px |
| 10rem | 160px |
| 15rem | 240px |
| 20rem | 320px |
| 30rem | 480px |
| 40rem | 640px |
| 50rem | 800px |
| 60rem | 960px |
| 80rem | 1280px |
| 100rem | 1600px |
Pixels (PX) to REM
| Pixels | REM |
| 1px | 0.0625rem |
| 2px | 0.125rem |
| 3px | 0.1875rem |
| 4px | 0.25rem |
| 5px | 0.3125rem |
| 6px | 0.375rem |
| 8px | 0.5rem |
| 10px | 0.625rem |
| 12px | 0.75rem |
| 14px | 0.875rem |
| 15px | 0.9375rem |
| 16px | 1rem |
| 18px | 1.125rem |
| 20px | 1.25rem |
| 24px | 1.5rem |
| 25px | 1.5625rem |
| 28px | 1.75rem |
| 32px | 2rem |
| 36px | 2.25rem |
| 40px | 2.5rem |
| 44px | 2.75rem |
| 48px | 3rem |
| 50px | 3.125rem |
| 56px | 3.5rem |
| 64px | 4rem |
| 72px | 4.5rem |
| 75px | 4.6875rem |
| 80px | 5rem |
| 90px | 5.625rem |
| 100px | 6.25rem |
What is REM in CSS?
REM (Root Em) is a CSS unit of measurement that is relative to the root element (<html>) font size. It is commonly used in web design to create scalable and flexible layouts, ensuring that elements adjust proportionally based on the user’s settings or device preferences.
Here’s how REM works:
- REM: This unit is relative to the font size of the root element (usually the
<html>tag). For example, if the font size of the root element is set to 16px, then1remequals 16px. If you use2rem, it would be equal to 32px.
Using REM units provides consistent scaling across elements, especially when compared to absolute units like pixels (px). This is particularly useful for responsive design, where flexibility and adaptability to different screen sizes or user preferences are important.
Some key advantages of using REM:
- Consistency: REM ensures that scaling is consistent across the entire site because it references the root font size.
- Accessibility: It allows users to adjust font sizes based on their browser settings, making the website more accessible.
- Responsive Design: It works well with media queries and helps ensure that websites look good across different devices.
The difference between REM and EM:
- EM: EM is relative to the font size of the parent element, not the root element. This can sometimes lead to cascading size changes, making EM less predictable in complex layouts.
REM tends to be preferred for its simplicity and ease of control when designing responsive and accessible websites.
What are PX in CSS?
In CSS, PX (pixels) is an absolute unit of measurement used to define the size of elements. Unlike relative units such as EM and REM, PX provides fixed, non-scaling values that don’t change relative to the parent or root element. Here’s a breakdown of PX and its use cases:
Definition of PX:
- Pixels (PX): A pixel is a unit that corresponds to a single dot on a computer screen or display. In CSS, 1px represents one pixel of the display, regardless of screen resolution or size.
- Fixed Size: Unlike EM and REM, which are relative units, PX is an absolute unit, meaning it sets a fixed size for an element, regardless of the context or surrounding elements.
Characteristics of PX:
- Absolute Measurement: PX provides an absolute value, meaning the size set using PX will remain the same, regardless of the surrounding environment or context (like parent elements).
- Non-Responsive: Since PX is an absolute unit, it doesn’t scale automatically based on the user’s screen size, resolution, or browser settings. For responsive designs, PX is often less flexible than relative units like REM or percentages.
- Precise Control: PX gives designers exact control over the sizing of elements. If you need a specific size, regardless of other factors, PX is a reliable option.
- Device-Dependent: While PX is considered an absolute unit, its actual size may vary slightly across devices with different screen densities (e.g., standard displays vs. Retina displays). Modern browsers and operating systems often use techniques like device pixel ratio (DPR) to ensure that CSS pixels render consistently on high-resolution displays.
Use Cases of PX:
- Precise Element Sizing: PX is ideal when you need exact dimensions for elements like buttons, icons, or images, where having fixed sizes is important for maintaining the design’s integrity.
- Example: Setting a button’s width and height to 100px by 40px guarantees that the button will always be exactly that size, regardless of the device or browser.
- Design Consistency: When creating pixel-perfect layouts where the designer requires precise and consistent sizing across different browsers, PX ensures that all elements render exactly as specified.
- Example: For logos, icons, or fixed headers and footers, where exact size and alignment are critical, PX ensures they appear as intended across different devices.
- Avoiding Scaling Issues: In some cases, using relative units like EM or REM might cause unintended scaling effects, especially in nested elements. PX can be used to avoid this issue by ensuring that elements remain fixed in size.
- Example: When designing small interface elements like toolbars, status bars, or tiny UI components where scaling is undesirable, PX ensures the elements maintain their intended size.
- When Responsiveness Isn’t Critical: PX is useful for components that do not need to scale or adapt to different screen sizes or resolutions, such as fixed-width sidebars, pixel-perfect graphics, or print-like layouts.
- Example: In some fixed-width websites or specific sections where responsive design is not necessary, PX allows for precise control without worrying about how the design will scale.
When to Avoid PX:
- Responsive Design: Since PX is an absolute unit, it doesn’t scale naturally with screen size or user preferences. For responsive design, using relative units like REM or percentages is generally better because they adjust based on the user’s device and settings.
- Accessibility: PX can limit accessibility since users who increase or decrease their browser’s default font size may not see changes in elements sized with PX. This can lead to issues with text readability or layout usability for users with visual impairments.
- Fluid Layouts: In modern web design, fluid and flexible layouts are more common, and PX can be rigid in comparison. For websites that need to adapt to various screen sizes and resolutions, relative units like REM or EM offer more flexibility.
Example of PX in CSS:
body {
font-size: 16px;
}
h1 {
font-size: 32px; /* Always 32px regardless of parent or screen size */
}
button {
width: 120px;
height: 40px;
padding: 10px;
}
Summary:
- Advantages:
- Provides exact control over element sizing.
- Ideal for fixed-size elements like icons, logos, and buttons.
- Useful in designs that require pixel-perfect accuracy.
- Disadvantages:
- Not responsive: Does not adjust automatically based on screen size or device.
- Accessibility limitations: Does not scale with user settings or browser preferences.
- Can lead to rigid designs that don’t adapt well to different environments.
In modern web development, while PX is still useful for certain fixed-size elements, it’s often used in combination with relative units like REM and EM to ensure both precision and responsiveness.
REM vs PX
| Aspect | REM (Root EM) | PX (Pixels) |
|---|---|---|
| Definition | REM is a relative unit of measurement based on the font size of the root element (typically the <html> element). |
PX is an absolute unit representing a fixed number of pixels on the screen. |
| Usage Context | Commonly used for scalable, responsive layouts where sizes need to adjust relative to the root element for consistency across the site. | Commonly used for precise, pixel-perfect designs where exact control over element size is needed. |
| Measurement Basis | Relative to the font size of the root element (default is usually 16px, unless explicitly changed). | Fixed size, independent of any other element, typically unaffected by browser settings. |
| Scalability | Automatically scales based on changes to the root font size, making it useful for responsive designs. | Does not scale inherently; requires media queries or other methods for responsive design adjustments. |
| Consistency | Consistent across the entire website because it is tied to the root element, ensuring uniform scaling. | Consistent across devices with the same resolution, but may appear differently on high-DPI or low-DPI screens. |
| Responsiveness | Naturally responsive, as changing the root font size scales the entire layout proportionally. | Not inherently responsive; requires media queries or relative units (e.g., REM, EM) to adapt to different screen sizes. |
| Precision | Provides scalable precision, allowing for consistent sizing that adapts across devices without losing proportionality. | Offers pixel-perfect precision, making it ideal for fixed layouts where exact control over element size is needed. |
| Common Applications | Best for responsive typography, layouts, and scalable spacing, where sizes need to adjust proportionally across the site. | Used in web design for precise element sizing, spacing, and font control, especially for pixel-perfect layouts. |
| Inheritance | REM values are always relative to the root element’s font size, ensuring consistent scaling across nested elements. | PX values do not inherit or scale; they remain fixed regardless of surrounding context or parent element. |
| Conversion | 1rem equals the root element’s font size (e.g., if the root font size is 16px, then 1rem = 16px). | 1px equals 1 screen pixel, no conversion is needed. |
| Scaling Behavior | Automatically scales with changes in the root font size, useful for creating fluid, responsive designs. | Does not scale unless explicitly adjusted, often appearing differently on screens with varying pixel densities. |
| Example | font-size: 1.5rem; /* 1.5 times the root font size (e.g., 1.5 * 16px = 24px) */ |
font-size: 16px; /* Fixed at 16 pixels regardless of root size */ |
| Best Used For | Best for consistent, scalable designs where changing the root size will proportionally scale the entire layout. | Best for precise, pixel-perfect designs where exact control over dimensions is needed and responsiveness is managed separately. |
Use Cases for REM and PX
Use Cases for REM:
REM units are particularly useful when you want consistent scaling across the entire webpage, as they always relate to the root font size (typically set on the <html> element).
Global Font Sizing:
- If you want to ensure consistent font sizing across different elements and maintain responsiveness, REM is ideal.
- For example, setting the body or root font size in pixels (e.g.,
16px) and using REM for headings, paragraphs, and other text allows uniform scaling across the entire page.
Example:
html { font-size: 16px; }
h1 { font-size: 2rem; } /* This equals 32px (2 * 16px) */
p { font-size: 1rem; } /* This equals 16px */
Responsive Design:
- REM is beneficial in creating responsive layouts. Since all elements scale according to the root font size, you can easily adjust the entire design by changing the root size in a media query.
- This is useful when designing for different screen sizes, such as mobile or desktop.
Example:
@media (max-width: 768px) {
html { font-size: 14px; } /* Adjusts all sizes based on the new root size */
}
Accessibility and User Preferences:
- REM supports accessibility by allowing users to adjust font sizes via browser settings. Since REM units scale according to the root element, changes in user preferences (such as increasing the default font size) will scale the entire design proportionally.
Consistent Spacing and Layout Elements:
- REM is often used for padding, margins, and other spacing-related properties to ensure consistency in layout, as everything scales from a single reference point (the root font size).
Example:
.container {
padding: 2rem; /* Scales with the root font size */
}
Use Cases for PX (Pixels):
PX is one of the most commonly used CSS units for web design. It represents an absolute unit of measurement, where 1px is a fixed, non-scalable value. While PX units don’t scale with user preferences, they are reliable for maintaining precise control over design elements.
Pixel-Perfect Designs:
Use PX when you need precise control over the layout, ensuring that elements display exactly as intended on different devices. This is common for graphic-heavy designs, buttons, and icons where specific sizing is critical.
Example:
.icon {
width: 32px;
height: 32px;
}
Fixed-Width Layouts:
When creating fixed-width layouts (e.g., landing pages or banners) that need to maintain exact dimensions regardless of screen size or resolution, PX is often preferred. It ensures that elements remain the same size across different devices.
Example:
.container {
width: 960px;
}
Fonts with Fixed Sizes:
PX is often used for font sizes in specific elements where precise control is required, such as in logos, headings, or UI components where the font needs to remain consistent across different devices and browsers. However, PX can hinder accessibility if used too broadly in typography, as it doesn’t adapt to user settings.
Example:
h1 {
font-size: 36px;
}
Raster Images and Icon Sizing:
When dealing with raster images (PNG, JPG) or pixel-based icons, PX is ideal because images are based on pixels, and sizing them in PX ensures no distortion or scaling that could compromise image quality.
Example:
img {
width: 300px;
height: auto;
}
User Interface (UI) Components:
In UI design, many UI components (e.g., buttons, toolbars, form elements) are designed using PX values to ensure consistency across different browsers and screen resolutions, especially when maintaining pixel-perfect rendering is crucial.
Example:
.button {
padding: 10px 20px;
}
Legacy or Non-Responsive Designs:
Older websites or designs that aren’t responsive often use PX because it’s simple to implement and ensures consistent dimensions. Although this approach is not ideal for modern responsive designs, it can still be useful in controlled environments.
FAQ on REM to PX
What is a REM to PX Converter?
A REM to PX Converter is a tool that translates REM units into pixels. We use REM units to create scalable and responsive web designs. This helps maintain consistency across CSS stylesheets, ensuring that typography and layout adjust smoothly based on the base font size.
How does a REM to PX Converter work?
It calculates the pixel equivalent of a REM unit based on the base font size defined in the HTML or CSS. For example, if the base font size is 16px, then 1 REM equals 16 pixels. Simple, right? Just input your REM value and get the PX equivalent instantly.
Why should I use REM units over PX?
REM units are a responsive design marvel. They allow the layout to scale based on user settings, making the interface more accessible. When you use REM units, your design adapts to different devices and settings seamlessly, maintaining that slick, professional look.
What is the default REM to PX value?
By default, 1 REM equals 16 pixels. This is based on the typical browser default font size. However, this can vary if the base font size is adjusted in the CSS. Knowing this helps in designing consistent and accessible webpages.
Can I change the base font size in CSS?
Yes, you can. By altering the base font size in your CSS, every REM unit will adjust accordingly. For instance, setting the base font size to 20px means 1 REM equals 20 pixels. Use the html tag in CSS to set this: html { font-size: 20px; }.
What’s the difference between REM and EM units?
REM units are relative to the HTML root element’s font size, while EM units are relative to the parent element’s font size. This distinction makes REM units more predictable, especially when dealing with nested elements in CSS.
How do REM units enhance responsive design?
Using REM units helps create a responsive design that adapts to various screen sizes and user settings. This approach ensures that typography scales smoothly, making your website user-friendly across multiple devices, from desktops to mobile phones.
When should I use PX instead of REM?
Use PX for pixel-perfect precision when necessary. Elements like borders or small icons might benefit from pixel units for exact sizing. For flexible and scalable designs, though, REM units are a better fit, especially for text and layout components.
Are there any tools to convert REM to PX?
Yes, there are several online tools, plugins, and even calculators you can use. They’re handy for quick conversions, helping you switch between REM and PX easily. Many web development resources and frameworks also include built-in converters.
How do I include a REM to PX Converter in my project?
Including a REM to PX Converter can be simple. You can implement a JavaScript function or use a CSS framework that supports this conversion. This is incredibly helpful when creating adaptive designs and ensuring consistency in typography settings across different sections of your site.
