30-seconds-of-code/snippets/constant-width-to-height-ratio.md

title, tags

title	tags
Constant width to height ratio	layout,beginner

Given an element of variable width, it will ensure its height remains proportionate in a responsive fashion (i.e. its width to height ratio remains constant).

<div class="constant-width-to-height-ratio"></div>

.constant-width-to-height-ratio {
  background: #333;
  width: 50%;
}

.constant-width-to-height-ratio:before {
  content: '';
  padding-top: 100%;
  float: left;
}

.constant-width-to-height-ratio:after {
  content: '';
  display: block;
  clear: both;
}

Explanation

• padding-top on the :before pseudo-element causes the height of the element to equal a percentage of its width. 100% therefore means the element's height will always be 100% of the width, creating a responsive square.
• This method also allows content to be placed inside the element normally.