Make floating divs the same height

Question

I have 2 divs side by side. I don't know the height of them upfront, it changed according to the content. Is there a way to make sure they will always be the same height, even when one of them stretches, only with CSS?

I made a fiddle to show. I want the red and blue divs to be the same height...

http://jsfiddle.net/7RVh4/

this is the css:

#wrapper {
width: 300px;
}
#left {
    width:50px;
    background: blue;
    float:left;
    height: 100%;  /* sadly, this doesn't work... */
}
#right {
    width:250px;
    background: red;
    float:left;
}

Answer 1

You could try instead of using float, use display: table-cell. You might find some older browsers don't understand this rule however. See below:

#wrapper {
    display: table; // See FelipeAls comment below
    width: 300px;
}

#left {
    display: table-cell;
    width: 50px;
    background: blue;
}

#right {
    display: table-cell;
    width: 250px;
    background: red;
}

Answer 2

Antony answer works ok, but you need all the divs to have the same parent and to have a wrapper, I have a solution that use javascript but works with any kind of element, they just need to have the same selector.

  function setEqualHeight(selector, triggerContinusly) {

    var elements = $(selector)
    elements.css("height", "auto")
    var max = Number.NEGATIVE_INFINITY;

    $.each(elements, function(index, item) {
        if ($(item).height() > max) {
            max = $(item).height()
        }
    })

    $(selector).css("height", max + "px")

    if (!!triggerContinusly) {
        $(document).on("input", selector, function() {
            setEqualHeight(selector, false)
        })

       $(window).resize(function() {
            setEqualHeight(selector, false)
       })
    }


}

    setEqualHeight(".sameh", true) 

http://jsfiddle.net/83WbS/2/

Answer 3

I would recommend reading this article that explains how to do what you are trying to do. I would put a fiddle up that shows, but its pretty extensive and pure css. http://matthewjamestaylor.com/blog/equal-height-columns-cross-browser-css-no-hacks

Answer 4

There is a much simpler solution I want to point to. Using large padding-bottom: 500em and negative margin-bottom:-500em of the same amount on columns while the wrapper has simply overflow:hidden to cut the columns to the right size.

Found here: HTML/CSS: Making two floating divs the same height

Answer 5

As indicated by Hexodus you can padding-bottom and margin-bottom, but a better solution would be to use flexbox or grid.

You can check this codepen if you want. I included a footer area because that is something I needed and it required a little bit more of hack.

.section {
  width: 500px;
  margin: auto;
  overflow: hidden;
  padding: 0;
}

div {
  padding: 1rem;
}

.header {
  background: lightblue;
}

.sidebar {
  background: lightgreen;
  width: calc(25% - 1rem);
}

.sidebar-left {
  float: left;
  padding-bottom: 500rem;
  margin-bottom: -500rem;
}

.main {
  background: pink;
  width: calc(50% - 4rem);
  float: left;
  padding-bottom: 500rem;
  margin-bottom: -500rem;
}

.sidebar-right {
  float: right;
  padding-bottom: 500rem;
  margin-bottom: -500rem;
}

.footer {
  background: black;
  color: white;
  float: left;
  clear: both;
  margin-top: 1rem;
  width: calc(100% - 2rem);
}

<div class="section">
<div class="header">
  This is the header
</div>
<div class="sidebar sidebar-left">
  This sidebar could have a menu or something like that. It may not have the same length as the other
</div>
<div class="main">
  This is the main area. It should have the same length as the sidebars
</div>
<div class="sidebar sidebar-right">
  This is the other sidebar, it could have some ads
</div>
<div class="footer">
  Footer area
</div>
</div>

Answer 6

You can do this without using tables, by using this CSS trick.

Example - http://jsfiddle.net/LMGsv/

HTML

   <div id="wrapper">
            <div id="columns">
                <div id="left">text</div>
                <div id="right">text<br/>another line<br /></div>
            </div>        
    </div>

CSS

#wrapper {
    float:left;
    width: 300px;
}
#columns {
    float:left;
    width:300px;
    background:blue;
}
#left {
    float:left;
    width:50px;
    background: blue;
}
#right {
    width:250px;
    background: red;
    float:left
}