All HTML elements can be considered as boxes. 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 HTML elements, and it consists of:
margins, borders, padding, and the actual content.
The box model allows us to place a border around elements and space elements in relation to other
The image below illustrates the box model:
Explanation of the different parts:
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 specify the width and height properties of an element with CSS, you
are just setting the width and height of the content area. To know the full size of the element,
you must also add the padding, border and margin.
The total width of the element in the example below is 300px:
Let's do the math:250px (width)+ 20px (left and right padding)+ 10px (left and
right border)+ 20px (left and right margin)= 300px
Imagine that you only had 250px of space. Let's make an element with a total width of 250px:
The total width of an element should always 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 always be calculated like this:
Total element height = height + top padding + bottom padding + top border + bottom border + top
margin + bottom margin
If you tested the previous example in Internet Explorer, you saw that the total width was not
IE includes padding and border in the width, when the width property is set, unless a DOCTYPE
To fix this problem, just add a DOCTYPE to the code:
Your Query was successfully sent!