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 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
Media visual
Computed value the percentage as specified or the absolute length
Animation type a length
Canonical order the 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 Internet Explorer Opera Safari
Basic support 1 Yes 1 3 3.5 1
auto 1 ? 1 61 3.5 1
Feature Android webview Chrome for Android Edge mobile Firefox for Android IE mobile Opera Android iOS Safari
Basic support 1 ? Yes 4 6 6 1
auto ? ? ? 4 ? ? ?

1. The auto value is not supported in quirks mode.

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