How to center a "position: absolute" element

If you have set a width you may use:

position: absolute;
margin-left: auto;
margin-right: auto;
left: 0;
right: 0;
text-align: center;

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Without knowing the width/height of the positioned¹ element, it is still possible to align it as follows:

EXAMPLE HERE

.child {
    position: absolute;
    top: 50%;  /* position the top  edge of the element at the middle of the parent */
    left: 50%; /* position the left edge of the element at the middle of the parent */

    transform: translate(-50%, -50%); /* This is a shorthand of
                                         translateX(-50%) and translateY(-50%) */
}

It's worth noting that CSS Transform is supported in IE9 and above. (Vendor prefixes omitted for brevity)

Explanation

Adding top/left of 50% moves the top/left margin edge of the element to the middle of the parent, and translate() function with the (negative) value of -50% moves the element by the half of its size. Hence the element will be positioned at the middle.

This is because a percentage value on top/left properties is relative to the height/width of the parent element (which is creating a containing block).

While a percentage value on translate() transform function is relative to width/height of the element itself (Actually it refers to the size of bounding box).

For unidirectional alignment, go with translateX(-50%) or translateY(-50%) instead.

^{1. An element with a position other than static. I.e. relative, absolute, fixed values.}

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Centering something absolutely positioned is rather convoluted in CSS.

ul#slideshow li {
    position: absolute;
    left:50%;
    margin-left:-20px;

}

Change margin-left to (negative) half the width of the element you are trying to center.

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Div vertically and horizontally aligned center

top: 0;
bottom: 0;
margin: auto;
position: absolute;
left: 0;
right: 0;

Note : Elements should have width and height to be set

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If you want to center an absolute element

#div {
    position:absolute;
    top:0;
    bottom:0;
    left:0;
    right:0;
    width:300px; /* Assign a value */
    height:500px; /* Assign a value */
    margin:auto;
}

If you want a container to be centered left to right, but not with top to bottom

#div {
    position:absolute;
    left:0;
    right:0;
    width:300px; /* Assign a value */
    height:500px; /* Assign a value */
    margin:auto;
}

If you want a container to be centered top to bottom, regardless of being left to right

#div {
    position:absolute;
    top:0;
    bottom:0;
    width:300px; /* Assign a value */
    height:500px; /* Assign a value */
    margin:auto;
}

Update as of December 15, 2015

Well I learnt this another new trick few months ago. Assuming that you have a relative parent element.

Here goes your absolute element.

.absolute-element { 
    position:absolute; 
    top:50%; 
    left:50%; 
    transform:translate(-50%, -50%); 
    width:50%; /* You can specify ANY width values here */ 
}

With this, I think it's a better answer than my old solution. Since you don't have to specify width AND height. This one it adapts the content of the element itself.

Update as of April 23, 2021

It does not answer to OP's question about position absolute, but if you want alternative solution, there's this called flexbox. Here's an example.

#parent {
    display:flex;
    align-items:center;
    justify-content:center;
}

What it does is the container is converted to flex and to align child items to center on horizontal is by using justify-content:center and vertical is to use align-items:center. It does support modern browsers too, so it's safe to use.

Though, be sure to read how flexbox work first.

https://developer.mozilla.org/en-US/docs/Learn/CSS/CSS_layout/Flexbox

Flexbox supported browsers

https://caniuse.com/flexbox

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A simple CSS trick, just add:

width: 100%;
text-align: center;

This works on both images and text.

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To center a “position: absolute” element.

.your-element {
  position: absolute;
  left: 0;
  right: 0;
  text-align: center; // or this ->  margin: 0 auto;
}

---

This worked for me:

position: absolute;
left: 50%;
transform: translateX(-50%);

---

to center a a position:absolute attribute you need to set left:50% and margin-left: -50% of the width of the div.

<!-- for horizontal -->
<style>
div.center{
 width:200px;
 left:50%;
 margin-left:-100px;
 position:absolute;
}
</style>


<body>
 <div class='center'>
  should be centered horizontaly
 </div>
</body>

for vertical center absolute you need to do the same thing bud not with left just with top. ( NOTE: html and body must have min-height 100%; )

<!-- for vertical -->
<style>
 body,html{
  min-height:100%;
 }
 div.center{
  height:200px;
  top:50%;
  margin-top:-100px;
  position:absolute;
 }
</style>

<body>
 <div class='center'>
  should be centered verticaly
 </div>
</body>

and can be combined for both

   <!-- for both -->
 <style>
 body,html{
  min-height:100%;
 }
 div.center{
  width:200px;
  height:50px
  left:50%;
  top:50%;
  margin-left:-100px;
  margin-top:-25px;
  position:absolute;
 }
</style>


<body>
 <div class='center'>
  should be centered
 </div>
</body>

---

Or you can now use flex box with postion absolute:

.parent {
    position: relative;
    display: flex;
    justify-content: center;
}

.child {
    position: absolute;
}

---

    <div class="centered_content"> content </div>
    <style type="text/css">
    .centered_content {
       text-align: center;
       position: absolute;
       left: 0;
       right: 0;
    }
    </style>

see demo on: http://jsfiddle.net/MohammadDayeh/HrZLC/

text-align: center; works with a position: absolute element when adding left: 0; right: 0;

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The simpler, the best:

img {
            top: 0;
            bottom: 0;
            left: 0;
            right: 0;
            margin: auto auto;
            position: absolute;
}

Then you need to insert your img tag into a tag that sports position:relative property, as follows:

<div style="width:256px; height: 256px; position:relative;">
      <img src="photo.jpg"/>
</div>

---

You can use the "transform" attribute:

position: absolute;
top: 50%;
left: 50%;
-webkit-transform: translateX(-50%) translateY(-50%);
transform: translateX(-50%) translateY(-50%);

---

probably the shortest

position:absolute;
left:0;right:0;top:0;bottom:0;
margin:0 auto;

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If you don't know the width of the element you can use this code:

<body>
<div style="position: absolute; left: 50%;">
    <div style="position: relative; left: -50%; border: dotted red 1px;">
        I am some centered shrink-to-fit content! <br />
        tum te tum
    </div>
</div>

Demo at fiddle: http://jsfiddle.net/wrh7a21r/

Source: https://stackoverflow.com/a/1777282/1136132

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Using left: calc(50% - Wpx/2); where W is the width of the element works for me.

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https://i.stack.imgur.com/masgh.gif

I'm not sure what you want to accomplish, but in this case just adding width: 100%; to your ul#slideshow li will do the trick.

Explanation

The img tags are inline-block elements. This means that they flow inline like text, but also have a width and height like block elements. In your css there are two text-align: center; rules applied to the <body> and to the #slideshowWrapper (which is redundant btw) this makes all inline and inline-block child elements to be centered in their closest block elements, in your code these are li tags. All block elements have width: 100% if they are the static flow (position: static;), which is default. The problem is that when you tell li tags to be position: absolute;, you take them out of normal static flow, and this causes them to shrink their size to just fit their inner content, in other words they kind of "lose" their width: 100% property.

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Your images are not centered because your list items are not centered; only their text is centered. You can achieve the positioning you want by either centering the entire list or centering the images within the list.

A revised version of your code can be found at the bottom. In my revision I center both the list and the images within it.

The truth is you cannot center an element that has a position set to absolute.

But this behavior can be imitated!

Note: These instructions will work with any DOM block element, not just img.

Surround your image with a div or other tag (in your case a li).

Note: The names given to these elements are not special. Alter your css or scss to give the div absolute positioning and your image centered. .absolute-div { position: absolute; width: 100%; // Range to be centered over. // If this element's parent is the body then 100% = the window's width // Note: You can apply additional top/bottom and left/right attributes // i.e. - top: 200px; left: 200px; // Test for desired positioning. } .absolute-div img { width: 500px; // Note: Setting a width is crucial for margin: auto to work. margin: 0 auto; }

And there you have it! Your img should be centered!

Your code:

Try this out:

body { text-align : center; } #slideshow { list-style : none; width : 800px; // alter to taste margin : 50px auto 0; } #slideshow li { position : absolute; } #slideshow img { border : 1px solid #CCC; padding : 4px; height : 500px; width : auto; // This sets the width relative to your set height. // Setting a width is required for the margin auto attribute below. margin : 0 auto; }

• 
• 

I hope this was helpful. Good luck!

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as many others said this ⬇️

.element {
  position: absolute;
  left: 0;
  top: 0;
  transform: translate(-50%, -50%);
}

should work. But be aware, that the .element must be in a wrapper that has position: relative; (in case you don't want to make it in the center of the whole HTML page)

FYI: I've made a pseudo-library for CSS centering. I needed it for my dev juniors. So, feel free to check it out. http://dev.solcode.net/centercss/

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An absolute object inside a relative object is relative to its parent, the problem here is that you need a static width for the container #slideshowWrapper , and the rest of the solution is like the other users says

body {
    text-align: center;
}

#slideshowWrapper {
    margin-top: 50px;
    text-align:center;
    width: 500px;
}

ul#slideshow {
    list-style: none;
    position: relative;
    margin: auto;
}

ul#slideshow li {
    position: relative;
    left: 50%;
}

ul#slideshow li img {
    border: 1px solid #ccc;
    padding: 4px;
    height: 450px;
}

http://jsfiddle.net/ejRTU/10/

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Here is easy and best solution for center element with “position: absolute”

body,html{ min-height:100%; } div.center{ width:200px; left:50%; margin-left:-100px;/*this is 50% value for width of the element*/ position:absolute; background:#ddd; border:1px solid #999; height:100px; text-align:center }

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Just use display: flex and justify-content: center on the parent element

body { text-align: center; } #slideshowWrapper { margin-top: 50px; text-align: center; } ul#slideshow { list-style: none; position: relative; margin: auto; display: flex; justify-content: center; } ul#slideshow li { position: absolute; } ul#slideshow li img { border: 1px solid #ccc; padding: 4px; height: 100px; }

You can find this solution in JSFIDDLE

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You can try this way :

* { margin: 0px; padding: 0px; } #body { height: 100vh; width: 100vw; position: relative; text-align: center; background-image: url('https://s-media-cache-ak0.pinimg.com/originals/96/2d/ff/962dff2247ad680c542622e20f44a645.jpg'); background-size: cover; background-repeat: no-repeat; } .text { position: absolute; top: 0; bottom: 0; left: 0; right: 0; height:100px; display: inline-block; margin: auto; z-index: 999999; }

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1- when you know the width of the absolutely positioned element.

width: 200px;
position: absolute;
left: 50%;
margin-left: -100px

2- when you don’t know the width of the absolutely positioned element. Excellent for responsiveness but is CSS3 older browsers may have an issue.

position: absolute;
left: 50%;
-webkit-transform: translateX(-50%);
transform: translateX(-50%)

3- when you don’t know the width of the absolutely positioned element but makes it 100% wide of it’s parent which might not fit the design.

position: absolute;
left: 0;
right: 0;
margin: auto

If you do know the width, you can use the third option as well and it will center.

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For this case, I think the code as below is enough:

    ul#slideshow li {
      position: absolute;
      left: 0;
      right: 0;
    }

---

#parent
{
    position : relative;
    height: 0;
    overflow: hidden;
    padding-bottom: 56.25% /* images with aspect ratio: 16:9  */
}

img 
{
    height: auto!important;
    width: auto!important;
    min-height: 100%;
    min-width: 100%;
    position: absolute;
    display: block;
    /*  */
    top: -9999px;
    bottom: -9999px;
    left: -9999px;
    right: -9999px;
    margin: auto;
}

I don't remember where I saw the centering method listed above, using negative top, right, bottom, left values. For me, this tehnique is the best, in most situations.

When I use the combination from above, the image behaves like a background-image with the following settings:

background-position: 50% 50%;
background-repeat: no-repeat;
background-size: cover;

More details about the first example can be found here:
Maintain the aspect ratio of a div with CSS

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My favorite method to absolute center any element or group of elements is to absolute position their container, make it the height and width of the relative container, then use flex to align the elements within.

In this specific case:

body {
  position: relative; /* OPTIONAL */
}

#slideshowWrapper {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: row; /* OPTIONAL IF ONLY ONE ELEMENT */
  justify-content: center;
  align-items: center;
}

Hope that helps, cheers.

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Position absolute takes it out of the flow, and places it at 0x0 to the parent ( Last block element to have a position absolute or position relative ).

I'm not sure what exactly you what you are trying to accomplish, It might be best to set the li to a position:relative and that will center them. Given your current CSS

Check out http://jsfiddle.net/rtgibbons/ejRTU/ to play with it

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What seems to be happening is there are two solutions; centered using margins and centered using position. Both work fine, but if you want to absolute position an element relative to this centered element, you need to use the absolute position method, because the absolute position of the second element defaults to the first parent that is positioned. Like so:

<!-- CENTERED USING MARGIN -->
<div style="width:300px; height:100px; border: 1px solid #000; margin:20px auto; text- align:center;">
    <p style="line-height:4;">width: 300 px; margin: 0 auto</p>
    <div style="position:absolute; width:100px; height:100px; background-color:#ff0000; top:-20px; left:0px;">
        <p style="line-height:4;">Absolute</p>
    </div>
</div>

<!-- CENTERED USING POSITION -->
<div style="position:absolute; left:50%; width:300px; height:100px; border: 1px solid #000; margin:20px 0 20px -150px; text-align:center;">
    <p style="line-height:2;">width:300px; position: absolute; left: 50%; margin-left:-150px;</p>
    <div style="position:absolute; width:100px; height:100px; background-color:#ff0000; top:0px; left:-105px;">
        <p style="line-height:4;">Absolute</p>
    </div>
</div>

Until I'd read this posting, using the margin:0 auto technique, to build a menu to the left of my content I had to build a same-width column to the right to balance it out. Not pretty. Thanks!

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Use margin-left: x%; where x is the half of the width of the element.

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