css17 CSS Height, Width

emanlee發表於2024-05-29
CSS

https://www.w3schools.com/css/css_dimension.asp

The CSS height and width properties are used to set the height and width of an element.

The CSS max-width property is used to set the maximum width of an element.

This element has a height of 50 pixels and a width of 100%.

<!DOCTYPE html>
<html>
<head>
<style>
div {
  height: 50px;
  width: 100%;
  border: 1px solid #4CAF50;
}
</style>
</head>
<body>

<h2>CSS height and width properties</h2>

<div>This div element has a height of 50 pixels and a width of 100%.</div>

</body>
</html>

CSS Setting height and width

The height and width properties are used to set the height and width of an element.

The height and width properties do not include padding, borders, or margins. It sets the height/width of the area inside the padding, border, and margin of the element.

CSS height and width Values

The height and width properties may have the following values:

  • auto - This is default. The browser calculates the height and width
  • length - Defines the height/width in px, cm, etc.
  • % - Defines the height/width in percent of the containing block
  • initial - Sets the height/width to its default value
  • inherit - The height/width will be inherited from its parent value

CSS height and width Examples

This element has a height of 200 pixels and a width of 50%

Example

Set the height and width of a <div> element:

div {
height: 200px;
width: 50%;
background-color: powderblue;
} 

<!DOCTYPE html>
<html>
<head>
<style>
div {
  height: 200px;
  width: 50%;
  background-color: powderblue;
}
</style>
</head>
<body>

<h2>Set the height and width of an element</h2>

<div>This div element has a height of 200px and a width of 50%.</div>

</body>
</html>

This element has a height of 100 pixels and a width of 500 pixels.

Example

Set the height and width of another <div> element:

div {
height: 100px;
width: 500px;
background-color: powderblue;
} 

<!DOCTYPE html>
<html>
<head>
<style>
div {
  height: 100px;
  width: 500px;
  background-color: powderblue;
}
</style>
</head>
<body>

<h2>Set the height and width of an element</h2>

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

</body>
</html>

Note: Remember that 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!

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 element has a height of 100 pixels and a max-width of 500 pixels.

Note: If you for some reason use both the width property and the max-width property on the same element, and the value of the width property is larger than the max-width property; the max-width property will be used (and the width property will be ignored).

Example

This <div> element has a height of 100 pixels and a max-width of 500 pixels:

div {
max-width: 500px;
height: 100px;
background-color: powderblue;
} 

<!DOCTYPE html>
<html>
<head>
<style>
div {
  max-width: 500px;
  height: 100px;
  background-color: powderblue;
}
</style>
</head>
<body>

<h2>Set the max-width of an element</h2>

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

<p>Resize the browser window to see the effect.</p>

</body>
</html>

Try it Yourself - Examples

Set the height and width of elements
This example demonstrates how to set the height and width of different elements.

Set the height and width of an image using percent
This example demonstrates how to set the height and width of an image using a percent value.

Set min-width and max-width of an element
This example demonstrates how to set a minimum width and a maximum width of an element using a pixel value.

Set min-height and max-height of an element
This example demonstrates how to set a minimum height and a maximum height of an element using a pixel value.

All CSS Dimension Properties

PropertyDescription
height Sets the height of an element
max-height Sets the maximum height of an element
max-width Sets the maximum width of an element
min-height Sets the minimum height of an element
min-width Sets the minimum width of an element
width Sets the width of an element

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