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.

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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>.


/* <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 */

/* 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.



The size of the margin as a fixed value.


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.


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

Formal definition

Initial value0
Applies toall elements, except elements with table display types other than table-caption, table and inline-table. It also applies to ::first-letter and ::first-line.
Percentagesrefer to the width of the containing block
Computed valuethe percentage as specified or the absolute length
Animation typea length

Formal syntax

margin-bottom = 
<length-percentage> |

<length-percentage> =
<length> |


Setting positive and negative bottom margins


<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>


CSS for divs to set margin-bottom and height

.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

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



Unknown specification
# margin-physical

Browser compatibility

BCD tables only load in the browser

See also