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Utilities

Bootstrap includes dozens of utilities—classes with a single purpose to reduce the frequency of highly repetitive declarations.

Sizing

Easily make an element as wide or as tall (relative to its parent) with our width and height utilities. Includes support for 25%, 50%, 75%, and 100% by default.

Width and height utilities are generated from the $sizes Sass map in _variables.scss. Modify those values as you need to generate different utilities here.

Width 25%
Width 50%
Width 75%
Width 100%
<div class="w-25 p-3" style="background-color: #eee;">Width 25%</div>
<div class="w-50 p-3" style="background-color: #eee;">Width 50%</div>
<div class="w-75 p-3" style="background-color: #eee;">Width 75%</div>
<div class="w-100 p-3" style="background-color: #eee;">Width 100%</div>
Height 25%
Height 50%
Height 75%
Height 100%
<div style="height: 100px; background-color: rgba(255,0,0,0.1);">
  <div class="h-25 d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1)">Height 25%</div>
  <div class="h-50 d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1)">Height 50%</div>
  <div class="h-75 d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1)">Height 75%</div>
  <div class="h-100 d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1)">Height 100%</div>
</div>

You can also use max-width: 100%; and max-height: 100%; utilities as needed.

Max-width 100%
<img class="mw-100" src="..." alt="Max-width 100%">
Max-height 100%
<div style="height: 100px; background-color: rgba(255,0,0,0.1);">
  <div class="mh-100" style="width: 100px; height: 200px; background-color: rgba(0,0,255,0.1);">Max-height 100%</div>
</div>