507

I have 2 divs side-by-side in a flexbox. The right hand one should always be the same width, and I want the left hand one to just grab the remaining space. But it won't unless I specifically set its width.

So at the moment, it's set to 96% which looks OK until you really squash the screen - then the right hand div gets a bit starved of the space it needs.

I guess I could leave it as it is but it feels wrong - like there has to be a way to say:

the right one is always the same; you on the left - you get everything that's left

.ar-course-nav {
  cursor: pointer;
  padding: 8px 12px 8px 12px;
  border-radius: 8px;
}
.ar-course-nav:hover {
  background-color: rgba(0, 0, 0, 0.1);
}
<br/>
<br/>
<div class="ar-course-nav" style="display:flex; justify-content:space-between;">
  <div style="width:96%;">
    <div style="overflow:hidden; white-space:nowrap; text-overflow:ellipsis;">
      <strong title="Course Name Which is Really Quite Long And Does Go On a Bit But Then When You Think it's Stopped it Keeps on Going for even longer!">
                Course Name Which is Really Quite Long And Does Go On a Bit But Then When You Think it's Stopped it Keeps on Going for even longer!
            </strong>
    </div>
    <div style="width:100%; display:flex; justify-content:space-between;">
      <div style="color:#555555; margin-right:8px; overflow:hidden; white-space:nowrap; text-overflow:ellipsis;" title="A really really really really really really really really really really really long department name">
        A really really really really really really really really really really really long department name
      </div>
      <div style="color:#555555; text-align:right; white-space:nowrap;">
        Created: 21 September 2016
      </div>
    </div>
  </div>
  <div style="margin-left:8px;">
    <strong>&gt;</strong>
  </div>
</div>
Michael Benjamin
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Adam Benson
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3 Answers3

752

Use the flex-grow property to make a flex item consume free space on the main axis.

This property will expand the item as much as possible, adjusting the length to dynamic environments, such as screen re-sizing or the addition / removal of other items.

A common example is flex-grow: 1 or, using the shorthand property, flex: 1.

Hence, instead of width: 96% on your div, use flex: 1.

You wrote:

So at the moment, it's set to 96% which looks OK until you really squash the screen - then the right hand div gets a bit starved of the space it needs.

The squashing of the fixed-width div is related to another flex property: flex-shrink

By default, flex items are set to flex-shrink: 1 which enables them to shrink in order to prevent overflow of the container.

To disable this feature use flex-shrink: 0.

For more details see The flex-shrink factor section in the answer here:

Learn more about flex alignment along the main axis here:

Learn more about flex alignment along the cross axis here:

Community
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Michael Benjamin
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    I had the same situation and using `flex-grow: 1` was not having the same effects than `flex: 1`. Do you maybe know why is it different? (I fixed my problem with the latter, thx) – WhGandalf Sep 12 '18 at 15:39
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    With `flex-grow: 1`, the `flex-basis` property remains at `auto`, its default value. With `flex: 1`, the `flex-basis` property changes to `0`. See my answer here for an in-depth review: https://stackoverflow.com/q/43520932/3597276 @WhGandalf – Michael Benjamin Sep 12 '18 at 22:26
  • flex-shrink was the key for me :) – pixelearth Apr 01 '19 at 05:33
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    Not only this but you'll also want to prevent an element from taking more space than is available using `min-width: 0` (or `min-height:0` is flex direction column), or else it will overflow beyond the available space in the layout, which is super weird honestly. https://stackoverflow.com/a/66689926/454780 – trusktr Feb 10 '22 at 18:56
  • But the children of an item will ignore the parent size, even with width/height to 100%. My case is about height: flex container with direction as column > Item with flex grow to 1 > child with height: 100%, height 100% is ignored. – Loenix Aug 07 '22 at 12:09
103

Basically I was trying to get my code to have a middle section on a 'row' to auto-adjust to the content on both sides (in my case, a dotted line separator). Like @Michael_B suggested, the key is using display:flex on the row container and at least making sure your middle container on the row has a flex-grow value of at least 1 higher than the outer containers (if outer containers don't have any flex-grow properties applied, middle container only needs 1 for flex-grow).

Here's a pic of what I was trying to do and sample code for how I solved it.

enter image description here

.row {
  background: lightgray;
  height: 30px;
  width: 100%;
  display: flex;
  align-items:flex-end;
  margin-top:5px;
}
.left {
  background:lightblue;
}
.separator{
  flex-grow:1;
  border-bottom:dotted 2px black;
}
.right {
  background:coral;
}
<div class="row">
  <div class="left">Left</div>
  <div class="separator"></div>
  <div class="right">Right With Text</div>
</div>
<div class="row">
  <div class="left">Left With More Text</div>
  <div class="separator"></div>
  <div class="right">Right</div>
</div>
<div class="row">
  <div class="left">Left With Text</div>
  <div class="separator"></div>
  <div class="right">Right With More Text</div>
</div>
HaulinOats
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3

Use this two lines for the element in the flex container:

flex-grow: 1; // Fill remaining space
min-width: 0; // Don't use more space than available
Luca Ziegler
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