Bootstrap Sizing: Width and Height

You can easily make an element as wide or as tall with width and height utilities. The classes include for 25%, 50%, 75%, 100%, and auto.

1. Width

Relative to the parent

<div class="w-25 p-3">Width 25%</div>
<div class="w-50 p-3">Width 50%</div>
<div class="w-75 p-3">Width 75%</div>
<div class="w-100 p-3">Width 100%</div>
<div class="w-auto p-3">Width auto</div>

You can also use max-width: 100%; utility as needed.

<div style="width: 50%; height: 100px;">
  <div class="mw-100" style="width: 200%;">Max-width 100%</div>
</div>

Relative to the viewport

<div class="min-vw-100">Min-width 100vw</div>
<div class="vw-100">Width 100vw</div>

2. Height

Relative to the parent

<div style="height: 100px;">
  <div class="h-25 d-inline-block" style="width: 120px;">Height 25%</div>
  <div class="h-50 d-inline-block" style="width: 120px;">Height 50%</div>
  <div class="h-75 d-inline-block" style="width: 120px;">Height 75%</div>
  <div class="h-100 d-inline-block" style="width: 120px;">Height 100%</div>
  <div class="h-auto d-inline-block" style="width: 120px;">Height auto</div>
</div>

You can also use max-height: 100%; utility as needed.

<div style="height: 100px;">
  <div class="mh-100" style="width: 100px; height: 200px;">Max-height 100%</div>
</div>

Relative to the viewport

<div class="min-vh-100">Min-height 100vh</div>
<div class="vh-100">Height 100vh</div>