Vue Bootstrap Sizing
Vue Sizing - Bootstrap 4 & Material Design
 Note: This documentation is for an older version of Bootstrap (v.4). A
    newer version is available for Bootstrap 5. We recommend migrating to the latest version of our product - Material Design for
      Bootstrap 5. 
 Go to docs v.5 
Easily make an element as wide or as tall (relative to its parent) with our width and height utilities.
Width and height utilities
Width and height utilities are generated from the
      $sizes Sass map in
      _variables.scss. Includes support for
      25%,
      50%,
      75%, and
      100% by default. Modify those values as you need to generate different utilities here.
        <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>
        <div class="w-auto p-3" style="background-color: #eee;">Width auto</div>
        <div class="w-responsive text-center mx-auto p-3 mt-2" style="background-color: #eee;">Width 75% on large devices and 100% on small ones</div>
      
        <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 class="h-auto d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1)">Height auto</div>
        </div>
      Mix max height and width
You can also use
    max-width: 100%; and
    max-height: 100%; utilities as needed.
        <img class="mw-100" src="https://placehold.it/2000x200" alt="Max-width 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>
      