description: Bootstrap includes a wide range of shorthand responsive margin and padding utility classes to modify an element's appearance.
group: utilities
toc: true
---
## 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 set `margin`
*`p` - for classes that set `padding`
Where *sides* is one of:
*`t` - for classes that set `margin-top` or `padding-top`
*`b` - for classes that set `margin-bottom` or `padding-bottom`
*`l` - for classes that set `margin-left` or `padding-left`
*`r` - for classes that set `margin-right` or `padding-right`
*`x` - for classes that set both `*-left` and `*-right`
*`y` - for classes that set both `*-top` and `*-bottom`
* blank - for classes that set a `margin` or `padding` on all 4 sides of the element
Where *size* is one of:
*`0` - for classes that eliminate the `margin` or `padding` by setting it to `0`
*`1` - (by default) for classes that set the `margin` or `padding` to `$spacer * .25`
*`2` - (by default) for classes that set the `margin` or `padding` to `$spacer * .5`
*`3` - (by default) for classes that set the `margin` or `padding` to `$spacer`
*`4` - (by default) for classes that set the `margin` or `padding` to `$spacer * 1.5`
*`5` - (by default) for classes that set the `margin` or `padding` to `$spacer * 3`
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`.