CSS3 box-sizing Property
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

