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CSS font-size-adjust Property

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Definition

The ratio between the height of the font's lowercase letter "x" and the height of the "font-size" is called a font's aspect value. If the aspect value is high, the font will be legible when it is set to a smaller size. For example: Verdana has an aspect value of 0.58 (means that when font size is 100 px, its x-height is 58 px). Times New Roman has an aspect value of 0.46. This means that Verdana is more legible at smaller sizes than Times New Roman.

The font-size-adjust property specifies an aspect value for an element that will preserve the x-height of the first-choice font.

Inherited: Yes

JavaScript Syntax

CSS properties can also be dynamically changed with a JavaScript.

Scripting Syntax: object.style.fontSizeAdjust="0.70"

In our HTML DOM tutorial you can find more details about the fontSizeAdjust property.

In our HTML DOM tutorial you can also find a full Style Object Reference.

Example

h2
{
font-size-adjust: 0.58
}

Possible Values

Value Description
none Default. Do not preserve the font's x-height if the font is unavailable
number Defines the aspect value ratio for the font

The formula to use:

font-size of first-choice font*(font-size-adjust/aspect value of available font) = font-size to apply to available font

Example:

If 14px Verdana (aspect value of 0.58) was unavailable, but an available font had an aspect value of 0.46, the font-size of the substitute would be 14 * (0.58/0.46) = 17.65px
 

Try-It-Yourself Demos

Set the size of the font using font-size-adjust
This example demonstrates how to set the size of a font using font-size-adjust.

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From http://www.w3schools.com (Copyright Refsnes Data)