Spacing
Bootstrap includes a wide range of shorthand responsive margin and padding utility classes to modify an element’s appearance.
How it works
Assign responsive-friendly
margin or
padding values to an element
or a subset of its sides with shorthand classes. Includes support
for individual properties, all properties, and vertical and
horizontal properties. Classes are built from a default Sass map
ranging from .25rem to
3rem.
Notation
Spacing utilities that apply to all breakpoints, from
xs to
xl, have no breakpoint
abbreviation in them. This is because those classes are applied from
min-width: 0 and up, and thus
are not bound by a media query. The remaining breakpoints, however,
do include a breakpoint abbreviation.
The classes are named using the format
{property}{sides}-{size} for
xs and
{property}{sides}-{breakpoint}-{size}
for sm,
md,
lg, and
xl.
Where property is one of:
-
m- for classes that setmargin -
p- for classes that setpadding
Where sides is one of:
-
t- for classes that setmargin-toporpadding-top -
b- for classes that setmargin-bottomorpadding-bottom -
l- for classes that setmargin-leftorpadding-left -
r- for classes that setmargin-rightorpadding-right -
x- for classes that set both*-leftand*-right -
y- for classes that set both*-topand*-bottom -
blank - for classes that set a
marginorpaddingon all 4 sides of the element
Where size is one of:
-
0- for classes that eliminate themarginorpaddingby setting it to0 -
1- (by default) for classes that set themarginorpaddingto$spacer * .25 -
2- (by default) for classes that set themarginorpaddingto$spacer * .5 -
3- (by default) for classes that set themarginorpaddingto$spacer -
4- (by default) for classes that set themarginorpaddingto$spacer * 1.5 -
5- (by default) for classes that set themarginorpaddingto$spacer * 3 -
auto- for classes that set themarginto auto
(You can add more sizes by adding entries to the
$spacers Sass map variable.)
Examples
Here are some representative examples of these classes:
.mt-0 {
margin-top: 0 !important;
}
.ml-1 {
margin-left: ($spacer * .25) !important;
}
.px-2 {
padding-left: ($spacer * .5) !important;
padding-right: ($spacer * .5) !important;
}
.p-3 {
padding: $spacer !important;
}
Horizontal centering
Additionally, Bootstrap also includes an
.mx-auto class for
horizontally centering fixed-width block level content—that is,
content that has
display: block and a
width set—by setting the
horizontal margins to auto.
<div class="mx-auto" style="width: 200px;">
Centered element
</div>
Negative margin
In CSS, margin properties can
utilize negative values (padding
cannot). As of 4.2, we’ve added negative margin utilities for every
non-zero integer size listed above (e.g.,
1,
2,
3,
4,
5). These utilities are ideal
for customizing grid column gutters across breakpoints.
The syntax is nearly the same as the default, positive margin
utilities, but with the addition of
n before the requested size.
Here’s an example class that’s the opposite of
.mt-1:
.mt-n1 {
margin-top: -0.25rem !important;
}
Here’s an example of customizing the Bootstrap grid at the medium
(md) breakpoint and above.
We’ve increased the
.col padding with
.px-md-5 and then
counteracted that with
.mx-md-n5 on the parent
.row.
<div class="row mx-md-n5">
<div class="col py-3 px-md-5 border bg-light">Custom column padding</div>
<div class="col py-3 px-md-5 border bg-light">Custom column padding</div>
</div>