MDN wants to learn about developers like you:

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

/* <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: unset;

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

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

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.
Percentagesrefer to the width of the containing block
Computed valuethe percentage as specified or the absolute length
Animation typea length
Canonical orderthe unique non-ambiguous order defined by the formal grammar


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 width of the containing block.
The browser selects a suitable value to use. See margin.

Formal syntax

<length> | <percentage> | auto



<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 {
.box1 {
.box2 {
    border:1px dashed black;
    border-width:1px 0;

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

.container {
    border:1px solid black;
div {


Specification Status Comment
CSS Basic Box Model
The definition of 'margin-bottom' in that specification.
Working Draft No significant change
CSS Transitions
The definition of 'margin-bottom' in that specification.
Working Draft Defines margin-bottom as animatable.
CSS Level 2 (Revision 1)
The definition of 'margin-bottom' in that specification.
Recommendation Removes its effect on inline elements.
CSS Level 1
The definition of 'margin-bottom' in that specification.
Recommendation Initial definition

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 1.0 (Yes) 1.0 (1.7 or earlier) 3.0 3.5 1.0 (85)
auto value 1.0 (Yes) 1.0 (1.7 or earlier) 6.0 (strict mode) 3.5 1.0 (85)
Feature Android Edge Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support 1.0 (Yes) 1.0 (1) 6.0 6.0 1.0

Document Tags and Contributors

 Last updated by: mfluehr,