Box Sizing

Utilities for controlling how the browser should calculate an element’s total size.

Use 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.

Use 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.

Tailwind lets you conditionally apply utility classes in different states using variant modifiers. For example, use to only apply the box-content utility on hover.

For a complete list of all available state modifiers, check out the Hover, Focus, & Other States documentation.

You can also use variant modifiers to target media queries like responsive breakpoints, dark mode, prefers-reduced-motion, and more. For example, use md:box-content to apply the utility at only medium screen sizes and above.