margin-bottom

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨July 2015⁩.

* Some parts of this feature may have varying levels of support.

The margin-bottom CSS property sets the margin area on the bottom of an element. A positive value places it farther from its neighbors, while a negative value places it closer.

Try it

margin-bottom: 1em;

margin-bottom: 10%;

margin-bottom: 10px;

margin-bottom: 0;

<section id="default-example">
  <div id="container">
    <div class="row"></div>
    <div class="row transition-all" id="example-element"></div>
    <div class="row"></div>
  </div>
</section>

#container {
  width: 300px;
  height: 200px;
  display: flex;
  align-content: flex-start;
  flex-direction: column;
  justify-content: flex-start;
}

.row {
  height: 33.33%;
  display: inline-block;
  border: solid #ce7777 10px;
  background-color: #2b3a55;
  flex-shrink: 0;
}

#example-element {
  border: solid 10px #ffbf00;
  background-color: #2b3a55;
}

The effect of the CSS margin-bottom property on the element box

This property has no effect on non-replaced inline elements, such as <span> or <code>.

Syntax

css

/* <length> values */
margin-bottom: 10px; /* An absolute length */
margin-bottom: 1em; /* relative to the text size */
margin-bottom: 5%; /* relative to the nearest block container's width */
margin-bottom: anchor-size(width);
margin-bottom: calc(anchor-size(--my-anchor self-block, 20px) / 3);

/* Keyword values */
margin-bottom: auto;

/* Global values */
margin-bottom: inherit;
margin-bottom: initial;
margin-bottom: revert;
margin-bottom: revert-layer;
margin-bottom: unset;

The margin-bottom property is specified as the keyword auto, or a <length>, or a <percentage>. Its value can be positive, zero, or negative.

Values

<length>

The size of the margin as a fixed value.

For anchor-positioned elements, the anchor-size() function resolves to a <length> value relative to the associated anchor element's width or height (see Setting element margin based on anchor size).

<percentage>

The size of the margin as a percentage, relative to the inline size (width in a horizontal language, defined by writing-mode) of the containing block.

auto

The browser selects a suitable value to use. See margin.

Formal definition

Initial value	`0`
Applies to	all elements, except elements with table `display` types other than `table-caption`, `table` and `inline-table`. It also applies to `::first-letter`.
Inherited	no
Percentages	refer to the width of the containing block
Computed value	the percentage as specified or the absolute length
Animation type	a length

Formal syntax

margin-bottom = 
  <length-percentage>  |
  auto                 |
  <anchor-size()>      

<length-percentage> = 
  <length>      |
  <percentage>  

<anchor-size()> = 
  anchor-size( [ <anchor-name> || <anchor-size> ]? , <length-percentage>? )  

<anchor-name> = 
  <dashed-ident>  

<anchor-size> = 
  width        |
  height       |
  block        |
  inline       |
  self-block   |
  self-inline

Examples

Setting positive and negative bottom margins

HTML

html

<div class="container">
  <div class="box0">Box 0</div>
  <div class="box1">Box 1</div>
  <div class="box2">Box one's negative margin pulls me up</div>
</div>

CSS

CSS for divs to set margin-bottom and height

css

.box0 {
  margin-bottom: 1em;
  height: 3em;
}
.box1 {
  margin-bottom: -1.5em;
  height: 4em;
}
.box2 {
  border: 1px dashed black;
  border-width: 1px 0;
  margin-bottom: 2em;
}

Some definitions for container and divs so margins' effects can be seen more clearly

css

.container {
  background-color: orange;
  width: 320px;
  border: 1px solid black;
}
div {
  width: 320px;
  background-color: gold;
}

Result

Specifications

Specification
CSS Box Model Module Level 3 # margin-physical

Browser compatibility

Help improve MDN

Learn how to contribute

This page was last modified on ⁨Oct 30, 2025⁩ by MDN contributors.

View this page on GitHub • Report a problem with this content