Example
Specify that <div> elements should have padding and border included in the element's total width and height:
div {
width: 300px;
height:
100px;
border: 1px solid blue;
box-sizing: border-box;
}
Try it Yourself »
More "Try it Yourself" examples below.
Definition and Usage
The box-sizing property is used to tell the browser what the sizing properties (width and height) should include.
Should they include the border-box? Or just the content-box (which is the default value of the width and height properties)?
| Default value: | content-box |
|---|---|
| Inherited: | no |
| Animatable: | no. Read about animatable |
| Version: | CSS3 |
| JavaScript syntax: | object.style.boxSizing="border-box" Try it |
Browser Support
The numbers in the table specify the first browser version that fully supports the property.
Numbers followed by -webkit- or -moz- specify the first version that worked with a prefix.
| Property | |||||
|---|---|---|---|---|---|
| box-sizing | 10.0 4.0 -webkit- |
8.0 | 29.0 2.0 -moz- |
5.1 3.2 -webkit- |
9.5 |
CSS Syntax
box-sizing: content-box|border-box|initial|inherit;
Property Values
| Value | Description |
|---|---|
| content-box | Default. The width and height properties (and min/max properties) includes only the content. Border, padding, or margin are not included |
| border-box | The width and height properties (and min/max properties) includes content, padding and border, but not the margin |
| initial | Sets this property to its default value. Read about initial |
| inherit | Inherits this property from its parent element. Read about inherit |
More Examples
Example
Specify two bordered boxes side by side:
div
{
box-sizing: border-box;
width: 50%;
float: left;
}
Try it Yourself »
Related Pages
CSS3 tutorial: CSS3 Box Sizing
HTML DOM reference: boxSizing property