Easily make an element as wide or as tall using the width and height Bootstrap utilities.
Relative to the parent
Width and height utilities are generated from the utility API in _utilities.scss. Includes support for 25%, 50%, 75%, 100%, and auto by default. Modify those values as you need to generate different utilities here.
Width 25%
Width 50%
Width 75%
Width 100%
Width auto
Height 25%
Height 50%
Height 75%
Height 100%
Height auto
You can also use max-width: 100%; and max-height: 100%; utilities as needed.
Max-height 100%
Relative to the viewport
You can also use utilities to set the width and height relative to the viewport.
html
<div class="min-vw-100">Min-width 100vw</div>
<div class="min-vh-100">Min-height 100vh</div>
<div class="vw-100">Width 100vw</div>
<div class="vh-100">Height 100vh</div>