THE WORLD'S LARGEST WEB DEVELOPER SITE

How TO - Aspect Ratio


Learn how to maintain the aspect ratio of an element with CSS.


Aspect Ratio

Create flexible elements that keep their aspect ratio (4:3, 16:9, etc.) when resized:

What is aspect ratio?

The aspect ratio of an element describes the proportional relationship between its width and its height. Two common video aspect ratios are 4:3 (the universal video format of the 20th century), and 16:9 (universal for HD television and European digital television).


How To - Height Equal to Width

Step 1) Add HTML:

Use a container element, like <div>, and if you want text inside of it, add a child element:

Example

<div class="container">
  <div class="text">Some text</div> <!-- If you want text inside the container -->
</div>


Step 2) Add CSS:

Add a percentage value for padding-top to maintain the aspect ratio of the DIV. The following example will create an aspect ratio of 1:1 (the height and width is always equal):

Example 1:1 Aspect Ratio

.container {
    background-color: red;
    width: 100%;
    padding-top: 100%; /* 1:1 Aspect Ratio */
    position: relative; /* If you want text inside of it */
}

/* If you want text inside of the container */
.text {
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
}
Try it Yourself »

Other aspect ratios:

Example 16:9 Aspect Ratio

.container {
    padding-top: 56.25%; /* 16:9 Aspect Ratio */
}
Try it Yourself »

Example 4:3 Aspect Ratio

.container {
    padding-top: 75%; /* 4:3 Aspect Ratio */
}
Try it Yourself »

Example 3:2 Aspect Ratio

.container {
    padding-top: 66.66%; /* 3:2 Aspect Ratio */
}
Try it Yourself »

Example 8:5 Aspect Ratio

.container {
    padding-top: 62.5%; /* 8:5 Aspect Ratio */
}
Try it Yourself »