---
layout: docs
title: Sizing
description: Easily make an element as wide or as tall with our width and height utilities.
group: utilities
toc: true
---
## 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.
{{< example class="bd-example-flex" >}}
Width 25%
Width 50%
Width 75%
Width 100%
Width auto
{{< /example >}}
{{< example >}}
Height 25%
Height 50%
Height 75%
Height 100%
Height auto
{{< /example >}}
You can also use `max-width: 100%;` and `max-height: 100%;` utilities as needed.
{{< example >}}
{{< placeholder width="100%" height="100" class="mw-100" text="Max-width 100%" >}}
{{< /example >}}
{{< example >}}
{{< /example >}}
## Relative to the viewport
You can also use utilities to set the width and height relative to the viewport.
```html
Min-width 100vw
Min-height 100vh
Width 100vw
Height 100vh
```
## Sass
### Utilities API
Sizing utilities are declared in our utilities API in `scss/_utilities.scss`. [Learn how to use the utilities API.]({{< docsref "/utilities/api#using-the-api" >}})
{{< scss-docs name="utils-sizing" file="scss/_utilities.scss" >}}