How To Get Screen Width In Css

In this blog post, we will explore how to get the screen width in CSS, which is a crucial aspect of responsive web design. Knowing the screen width enables you to create layouts that adapt to different device sizes effectively. CSS provides various techniques to achieve this objective. Let’s discuss some of the most popular methods:

1. Using Media Queries

Media Queries are a feature in CSS3 that allows you to apply styles based on specific conditions, such as screen width. The basic syntax for a media query is as follows:

@media (condition) {
    /* styles */

To target a specific screen width, you can use the min-width or max-width property. Here’s an example:

@media (min-width: 768px) {
    /* styles for screens with a width of 768 pixels or more */

@media (max-width: 767px) {
    /* styles for screens with a width of 767 pixels or less */

Using media queries, you can create breakpoints for different screen sizes and apply styles accordingly.

2. Using the vw Unit

The vw (viewport width) unit is a relative unit that represents a percentage of the viewport’s width. One unit of vw is equal to 1% of the viewport width. This unit allows you to create responsive designs that adjust based on the screen width. Here’s an example:

.container {
    width: 80vw; /* 80% of the viewport width */

The above code snippet sets the container’s width to 80% of the viewport width, making it responsive to different screen sizes.

3. Using CSS Variables (Custom Properties) and calc()

Another way to get the screen width in CSS is by using CSS variables (custom properties) and the calc() function. First, let’s define a custom property named –screen-width and set its value to 100vw:

:root {
    --screen-width: 100vw;

Now, you can use the calc() function to perform calculations using the screen width:

.container {
    width: calc(var(--screen-width) - 20vw); /* 80% of the viewport width */

This approach allows you to create more complex and responsive designs using CSS variables and calculations.


Getting the screen width in CSS is essential for responsive web design. In this post, we discussed three popular methods: media queries, the vw unit, and CSS variables with the calc() function. Each technique has its advantages, so choose the one that best suits your specific needs and requirements.