The <sup> HTML element specifies inline text which is to be displayed as superscript for solely typographical reasons. Superscripts are usually rendered with a raised baseline using smaller text.

This element only includes the global attributes.

The <sup> element should only be used for typographical reasons—that is, to change the position of the text to comply with typographical conventions or standards, rather than solely for presentation or appearance purposes.

For example, to style the wordmark of a business or product which uses a raised baseline should be done using CSS (most likely vertical-align) rather than <sup>. This would be done using, for example, vertical-align: super or, to shift the baseline up 50%, vertical-align: 50%.

Appropriate use cases for <sup> include (but aren't necessarily limited to):

• Displaying exponents, such as "x ³ ." It may be worth considering the use of MathML for these, especially in more complex cases. See Exponents under Examples below.
• Displaying superior lettering, which is used in some languages when rendering certain abbreviations. For example, in French, the word "mademoiselle" can be abbreviated "M ^lle "); this is an acceptable use case. See Superior lettering for examples.
• Representing ordinal numbers, such as "4 ^th " instead of "fourth." See Ordinal numbers for examples.

Exponents, or powers of a number, are among the most common uses of superscripted text. For example:

<p>
  One of the most common equations in all of physics is <var>E</var>=<var>m</var
  ><var>c</var><sup>2</sup>.
</p>

Result

Superior lettering is not technically the same thing as superscript. However, it is common to use <sup> to present superior lettering in HTML. Among the most common uses of superior lettering is the presentation of certain abbreviations in French:

<p>Robert a présenté son rapport à M<sup>lle</sup> Bernard.</p>

Result

Ordinal numbers, such as "fourth" in English or "quinto" in Spanish may be abbreviated using numerals and language-specific text rendered in superscript:

<p>
  The ordinal number "fifth" can be abbreviated in various languages as follows:
</p>
<ul>
  <li>English: 5<sup>th</sup></li>
  <li>French: 5<sup>ème</sup></li>
</ul>

Result

• The <sub> HTML element that produces subscripts. Note that you cannot use sub and sup at the same time: you need to use MathML to produce both a superscript and a subscript next to the chemical symbol of an element, representing its atomic number and its nuclear number.
• The <msub>, <msup>, and <msubsup> MathML elements.
• The CSS vertical-align property.