Spacing

Also see the official documentation

Documentation and examples for Bootstrap shorthand responsive margin and padding utility classes to modify an element’s appearance.

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
• 4px - (by default) for classes that set the margin or padding to 4px
• 8px - (by default) for classes that set the margin or padding to 8px
• 16px - (by default) for classes that set the margin or padding to 16px
• 24px - (by default) for classes that set the margin or padding to 24px
• 32px - (by default) for classes that set the margin or padding to 32px
• 48px - (by default) for classes that set the margin or padding to 48px
• auto - for classes that set the margin to auto

Examples

Here are some representative examples of these classes:

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.

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., 4px, 8px, 16px, 24px, 32px, 48px). 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-32px:

.mt-n32px {
  margin-top: -32px !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.