Css padding include in width

box-sizing

The box-sizing CSS property sets how the total width and height of an element is calculated.

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By default in the CSS box model, the width and height you assign to an element is applied only to the element’s content box. If the element has any border or padding, this is then added to the width and height to arrive at the size of the box that’s rendered on the screen. This means that when you set width and height , you have to adjust the value you give to allow for any border or padding that may be added. For example, if you have four boxes with width: 25%; , if any has left or right padding or a left or right border, they will not by default fit on one line within the constraints of the parent container.

The box-sizing property can be used to adjust this behavior:

• content-box gives you the default CSS box-sizing behavior. If you set an element’s width to 100 pixels, then the element’s content box will be 100 pixels wide, and the width of any border or padding will be added to the final rendered width, making the element wider than 100px.
• border-box tells the browser to account for any border and padding in the values you specify for an element’s width and height. If you set an element’s width to 100 pixels, that 100 pixels will include any border or padding you added, and the content box will shrink to absorb that extra width. This typically makes it much easier to size elements. box-sizing: border-box is the default styling that browsers use for the , , and elements, and for elements whose type is radio , checkbox , reset , button , submit , color , or search .

Note: It is often useful to set box-sizing to border-box to lay out elements. This makes dealing with the sizes of elements much easier, and generally eliminates a number of pitfalls you can stumble on while laying out your content. On the other hand, when using position: relative or position: absolute , use of box-sizing: content-box allows the positioning values to be relative to the content, and independent of changes to border and padding sizes, which is sometimes desirable.

Syntax

box-sizing: border-box; box-sizing: content-box; /* Global values */ box-sizing: inherit; box-sizing: initial; box-sizing: revert; box-sizing: revert-layer; box-sizing: unset; 

The box-sizing property is specified as a single keyword chosen from the list of values below.

Values

This is the initial and default value as specified by the CSS standard. The width and height properties include the content, but does not include the padding, border, or margin. For example, .box renders a box that is 370px wide.

Here, the dimensions of the element are calculated as: width = width of the content, and height = height of the content. (Borders and padding are not included in the calculation.)

The width and height properties include the content, padding, and border, but do not include the margin. Note that padding and border will be inside of the box. For example, .box renders a box that is 350px wide, with the area for content being 330px wide. The content box can’t be negative and is floored to 0, making it impossible to use border-box to make the element disappear.

Here the dimensions of the element are calculated as: width = border + padding + width of the content, and height = border + padding + height of the content.

Formal definition

Formal syntax

Examples

Box sizes with content-box and border-box

This example shows how different box-sizing values alter the rendered size of two otherwise identical elements.

HTML

div class="content-box">Content boxdiv> br /> div class="border-box">Border boxdiv> 

CSS

div  width: 160px; height: 80px; padding: 20px; border: 8px solid red; background: yellow; > .content-box  box-sizing: content-box; /* Total width: 160px + (2 * 20px) + (2 * 8px) = 216px Total height: 80px + (2 * 20px) + (2 * 8px) = 136px Content box width: 160px Content box height: 80px */ > .border-box  box-sizing: border-box; /* Total width: 160px Total height: 80px Content box width: 160px - (2 * 20px) - (2 * 8px) = 104px Content box height: 80px - (2 * 20px) - (2 * 8px) = 24px */ > 

Result

Specifications

Browser compatibility

BCD tables only load in the browser

See also

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CSS Box Sizing

The CSS box-sizing property allows us to include the padding and border in an element’s total width and height.

Without the CSS box-sizing Property

By default, the width and height of an element is calculated like this:

width + padding + border = actual width of an element
height + padding + border = actual height of an element

This means: When you set the width/height of an element, the element often appears bigger than you have set (because the element’s border and padding are added to the element’s specified width/height).

The following illustration shows two elements with the same specified width and height:

The two elements above end up with different sizes in the result (because div2 has a padding specified):

Example

.div1 <
width: 300px;
height: 100px;
border: 1px solid blue;
>

.div2 width: 300px;
height: 100px;
padding: 50px;
border: 1px solid red;
>

The box-sizing property solves this problem.

With the CSS box-sizing Property

The box-sizing property allows us to include the padding and border in an element’s total width and height.

If you set box-sizing: border-box; on an element, padding and border are included in the width and height:

Here is the same example as above, with box-sizing: border-box; added to both elements:

Example

.div1 <
width: 300px;
height: 100px;
border: 1px solid blue;
box-sizing: border-box;
>

.div2 width: 300px;
height: 100px;
padding: 50px;
border: 1px solid red;
box-sizing: border-box;
>

Since the result of using the box-sizing: border-box; is so much better, many developers want all elements on their pages to work this way.

The code below ensures that all elements are sized in this more intuitive way. Many browsers already use box-sizing: border-box; for many form elements (but not all — which is why inputs and text areas look different at width: 100%;).

Applying this to all elements is safe and wise:

Example

CSS Box Sizing Property

Property	Description
box-sizing	Defines how the width and height of an element are calculated: should they include padding and borders, or not

Источник

Does element width include padding in CSS ?

Cascading Style Sheets fondly referred to as CSS, is a simply designed language intended to simplify the process of making web pages presentable. CSS allows you to apply styles to the web pages. More importantly, CSS enables you to do this independent of the HTML that makes up each web page. It describes how a webpage should look. CSS lets developers and designers define how it behaves, including how elements are positioned in the browser.

In this article, we will learn about width property and find out whether element width includes padding or not.

Width of Element: The width property in CSS is used to set the width of the text, and images. The width can be assigned to the text and images in the form of pixels(px), percentage(%), centimetre(cm) etc. The width property does not contain padding, borders, or margins. The width property is overridden by the min-width and max-width properties. The width property, by default, sets the width for the content area, although if the value of the box-sizing is set to border-box then it will set the width of the border area.

Padding of Element: CSS paddings are used to create space around the element, inside any defined border. We can set different paddings for individual sides (top, right, bottom, left). It is important to add border properties to implement padding properties.

Does element width include padding? No, element width does not include padding, margin, or border. The basic difference between padding and width is that in padding you define the space around the element and on the other hand in the width you define the space of the element.

Property Used:

• width: This property is used to define the size of the element.
• padding: This property is used to define the space around the element

Example 1: Padding is not included when you apply the width property. Padding is applied only when you intentionally apply padding to any element.

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