Height equal to dynamic width (CSS fluid layout) [duplicate]

Answer 1

Using jQuery you can achieve this by doing

var cw = $('.child').width();
$('.child').css({'height':cw+'px'});

Check working example at http://jsfiddle.net/n6DAu/1/

Answer 2

It is possible without any Javascript :)

The HTML:

<div class='box'>
    <div class='content'>Aspect ratio of 1:1</div>
</div> 

The CSS:

.box {
    position: relative;
    width:    50%; /* desired width */
}

.box:before {
    content:     "";
    display:     block;
    padding-top: 100%; /* initial ratio of 1:1*/
}

.content {
    position: absolute;
    top:      0;
    left:     0;
    bottom:   0;
    right:    0;
}

/* Other ratios - just apply the desired class to the "box" element */
.ratio2_1:before{
    padding-top: 50%;
}
.ratio1_2:before{
    padding-top: 200%;
}
.ratio4_3:before{
    padding-top: 75%;
}
.ratio16_9:before{
    padding-top: 56.25%;
}

Answer 3

[Update: Although I discovered this trick independently, I’ve since learned that Thierry Koblentz beat me to it. You can find his 2009 article on A List Apart. Credit where credit is due.]

I know this is an old question, but I encountered a similar problem that I did solve only with CSS. Here is my blog post that discusses the solution. Included in the post is a live example. Code is reposted below.

#container {
  display: inline-block;
  position: relative;
  width: 50%;
}

#dummy {
  margin-top: 75%;
  /* 4:3 aspect ratio */
}

#element {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: silver/* show me! */
}

<div id="container">
  <div id="dummy"></div>
  <div id="element">
    some text
  </div>
</div>

Answer 4

really this belongs as a comment to Nathan's answer, but I'm not allowed to do that yet...
I wanted to maintain the aspect ratio, even if there is too much stuff to fit in the box. His example expands the height, changing the aspect ratio. I found adding

overflow: hidden;
overflow-x: auto;
overflow-y: auto;

to the .element helped. See http://jsfiddle.net/B8FU8/3111/

Answer 5

Expanding upon the padding top/bottom technique, it is possible to use a pseudo element to set the height of the element. Use float and negative margins to remove the pseudo element from the flow and view.

This allows you to place content inside the box without using an extra div and/or CSS positioning.

.fixed-ar::before {
  content: "";
  float: left;
  width: 1px;
  margin-left: -1px;
}
.fixed-ar::after {
  content: "";
  display: table;
  clear: both;
}


/* proportions */

.fixed-ar-1-1::before {
  padding-top: 100%;
}
.fixed-ar-4-3::before {
  padding-top: 75%;
}
.fixed-ar-16-9::before {
  padding-top: 56.25%;
}


/* demo */

.fixed-ar {
  margin: 1em 0;
  max-width: 400px;
  background: #EEE url(https://lorempixel.com/800/450/food/5/) center no-repeat;
  background-size: contain;
}

<div class="fixed-ar fixed-ar-1-1">1:1 Aspect Ratio</div>
<div class="fixed-ar fixed-ar-4-3">4:3 Aspect Ratio</div>
<div class="fixed-ar fixed-ar-16-9">16:9 Aspect Ratio</div>

Answer 6

width: 80vmin; height: 80vmin;

CSS does 80% of the smallest view, height or width

http://caniuse.com/#feat=viewport-units