CSS

CSS: Dimensions

The CSS dimension properties allow you to control the height and width of an element.
This element has a width of 100%.

Setting height and width

The height and width properties are used to set the height and width of an element.
The height and width can be set to auto (this is default. Means that the browser calculates the height and width), or be specified in length values, like px, cm, etc., or in percent (%) of the containing block.
This <div> element has a height of 100 pixels and a width of 500 pixels.
Note: The height and width properties do not include padding, borders, or margins; they set the height/width of the area inside the padding, border, and margin of the element!
The following example shows a <div> element with a height of 100 pixels and a width of 500 pixels:

Example:


<!DOCTYPE html>
<html>
<head>
<style>
div {
    width: 500px;
    height: 100px;
    border: 3px solid #73AD21;
}
</style>
</head>
<body>

<h2>Set height and width of an Element:</h2>

<div>
This div element has a height of 100px and a width of 500px.
</div>

</body>
</html>

Setting max-width

The max-width property is used to set the maximum width of an element.
The max-width can be specified in length values, like px, cm, etc., or in percent (%) of the containing block, or set to none (this is default. Means that there is no maximum width).
The problem with the </div> above occurs when the browser window is smaller than the width of the element (500px). The browser then adds a horizontal scrollbar to the page.
Using max-width instead, in this situation, will improve the browser's handling of small windows.
Tip: Drag the browser window to smaller than 500px wide, to see the difference between the two divs!
This </div> element has a height of 100 pixels and a max-width of 500 pixels.
Note: The value of the max-width property overrides width.
The following example shows a </div> element with a height of 100 pixels and a max-width of 500 pixels:

Example:


<!DOCTYPE html>
<html>
<head>
<style>
div {
    max-width: 500px;
    height: 100px;
    border: 3px solid #73AD21;
}
</style>
</head>
<body>

<h2>Set max-width of an Element:</h2>

<div>
This div element has a height of 100px and a max-width of 500px. 
Resize the browser window to see the effect.
</div>

</body>
</html>