BEST SITE FOR WEB DEVELOPERS

CSS Tutorial

CSS HOME CSS Introduction CSS Syntax CSS Selectors CSS How To CSS Comments CSS Colors CSS Backgrounds CSS Borders CSS Margins CSS Padding CSS Height/Width CSS Box Model CSS Outline CSS Text CSS Fonts CSS Icons CSS Links CSS Lists CSS Tables CSS Display CSS Max-width CSS Position CSS Z-index CSS Overflow CSS Float CSS Inline-block CSS Align CSS Combinators CSS Pseudo-class CSS Pseudo-element CSS Opacity CSS Navigation Bar CSS Dropdowns CSS Image Gallery CSS Image Sprites CSS Attr Selectors CSS Forms CSS Counters CSS Website Layout CSS Units CSS Specificity CSS !important CSS Math Functions

CSS Advanced

CSS Rounded Corners CSS Border Images CSS Backgrounds CSS Colors CSS Color Keywords CSS Gradients CSS Shadows CSS Text Effects CSS Web Fonts CSS 2D Transforms CSS 3D Transforms CSS Transitions CSS Animations CSS Tooltips CSS Style Images CSS Image Reflection CSS object-fit CSS object-position CSS Masking CSS Buttons CSS Pagination CSS Multiple Columns CSS User Interface CSS Variables CSS Box Sizing CSS Media Queries CSS MQ Examples CSS Flexbox

CSS Responsive

RWD Intro RWD Viewport RWD Grid View RWD Media Queries RWD Images RWD Videos RWD Frameworks RWD Templates

CSS Grid

Grid Intro Grid Container Grid Item

CSS SASS

SASS Tutorial

CSS Examples

CSS Templates CSS Examples CSS Quiz CSS Exercises CSS Certificate

CSS References

CSS Reference CSS Selectors CSS Functions CSS Reference Aural CSS Web Safe Fonts CSS Animatable CSS Units CSS PX-EM Converter CSS Colors CSS Color Values CSS Default Values CSS Browser Support

CSS Lessons for beginners

Ua

CSS Box Model


All HTML elements can be considered as boxes.


The CSS Box Model

In CSS, the term "box model" is used when talking about design and layout.

The CSS box model is essentially a box that wraps around every HTML element. It consists of: margins, borders, padding, and the actual content. The image below illustrates the box model:

Explanation of the different parts:

  • Content - The content of the box, where text and images appear
  • Padding - Clears an area around the content. The padding is transparent
  • Border - A border that goes around the padding and content
  • Margin - Clears an area outside the border. The margin is transparent

The box model allows us to add a border around elements, and to define space between elements. 

Example

Demonstration of the box model:

div {
  width: 300px;
  border: 15px solid green;
  padding: 50px;
  margin: 20px;
}
Try it Yourself »

Width and Height of an Element

In order to set the width and height of an element correctly in all browsers, you need to know how the box model works.

Important: When you set the width and height properties of an element with CSS, you just set the width and height of the content area. To calculate the full size of an element, you must also add padding, borders and margins.

Example

This <div> element will have a total width of 350px: 

div {
  width: 320px;
  padding: 10px;
 border: 5px solid gray;
  margin: 0;
}
Try it Yourself »

Here is the calculation:

320px (width)
+ 20px (left + right padding)
+ 10px (left + right border)
+ 0px (left + right margin)
= 350px

The total width of an element should be calculated like this:

Total element width = width + left padding + right padding + left border + right border + left margin + right margin

The total height of an element should be calculated like this:

Total element height = height + top padding + bottom padding + top border + bottom border + top margin + bottom margin


Test Yourself With Exercises

Exercise:

Set the width of the <div> element to "200px".

<style>
 {
  : ;
}
</style>

<body>

<div>
Lorem ipsum dolor sit amet,
consectetur adipiscing elit,
sed do eiusmod tempor incididunt
ut labore et dolore magna aliqua.
</div>

</body>