index.md

---

title: MathML Attribute Values
slug: Web/MathML/Attribute/Values
browser-compat: mathml.attribute_values

---

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MathML-specific types

In addition to CSS data types, some MathML attributes accept the following types:

• <unsigned-integer>: An <integer>, whose first character is neither U+002D HYPHEN-MINUS character (-) nor U+002B PLUS SIGN (+); for example 1234.

• <boolean>: A string true or false representing a boolean value.

Legacy MathML lengths

{{deprecated_header}}

Instead of <length-percentage>, MathML used to define its own type to describe lengths. Accepted values included non-zero unitless length values (e.g. 5 to mean 500%), values containing numbers ending with a dot (e.g. 34.px), or named spaces (e.g. thinmathspace). For compatibility reasons, it is recommended to replace non-zero unitless length values with equivalent <percentage> values, to remove unnecessary dots in numbers, and to use the following replacement for named lengths:

veryverythinmathspace  => 0.05555555555555555em
verythinmathspace      => 0.1111111111111111em
thinmathspace          => 0.16666666666666666em
mediummathspace        => 0.2222222222222222em
thickmathspace         => 0.2777777777777778em
verythickmathspace     => 0.3333333333333333em
veryverythickmathspace => 0.3888888888888889em

Units

Unit	Description
em	{{ Cssxref("font-size", "Font-relative") }} unit
ex	{{ Cssxref("font-size", "Font-relative") }} unit. (The "x"-height of the element, 1ex ≈ 0.5em in many fonts)
px	Pixels
in	Inches (1 inch = 2.54 centimeters)
cm	Centimeters
mm	Millimeters
pt	Points (1 point = 1/72 inch)
pc	Picas (1 pica = 12 points)
%	Percentage of the default value.

Constants

Constant	Value
veryverythinmathspace	1/18em
verythinmathspace	2/18em
thinmathspace	3/18em
mediummathspace	4/18em
thickmathspace	5/18em
verythickmathspace	6/18em
veryverythickmathspace	7/18em
negativeveryverythinmathspace	-1/18em
negativeverythinmathspace	-2/18em
negativethinmathspace	-3/18em
negativemediummathspace	-4/18em
negativethickmathspace	-5/18em
negativeverythickmathspace	-6/18em
negativeveryverythickmathspace	-7/18em

Browser compatibility

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