box-sizing

Examples

Including borders and padding

Use the box-border utility to set an element's box-sizing to border-box, telling the browser to include the element's borders and padding when you give it a height or width.

This means a 100px × 100px element with a 2px border and 4px of padding on all sides will be rendered as 100px × 100px, with an internal content area of 88px × 88px:

<div class="box-border size-32 border-4 p-4 ...">  <!-- ... --></div>

Tailwind makes this the default for all elements in our preflight base styles.

Excluding borders and padding

Use the box-content utility to set an element's box-sizing to content-box, telling the browser to add borders and padding on top of the element's specified width or height.

This means a 100px × 100px element with a 2px border and 4px of padding on all sides will actually be rendered as 112px × 112px, with an internal content area of 100px × 100px:

<div class="box-content size-32 border-4 p-4 ...">  <!-- ... --></div>

Responsive design

Prefix a box-sizing utility with a breakpoint variant like md: to only apply the utility at medium screen sizes and above:

<div class="box-content md:box-border ...">  <!-- ... --></div>

Learn more about using variants in the variants documentation.