Home : Technical Terms : Subscript Definition


A subscript is a character or string that is smaller than the preceding text and sits at or below the baseline. Subscripts have many scientific applications, including mathematics, computer science, and chemistry.

Below is an example of a math function that uses subscripts to define the Fibonacci sequence:

Fn = Fn-1 + Fn−2

The small "n" is a subscript. When used in the context "Fn," it refers to a function evaluated for the value "n." The text n-1 and n-2 are also subscripts that define previous values of "n" in the sequence.

In computer science, subscripts can be used to specify a number system. For example, the decimal or "denary" number 200 is equal to 11001000 in binary and C8 in hexadecimal. Instead of writing out the full words, you could describe the equality of the three numbers with the following statement:

20010 = 110010002 = C816

Subscripts are also used in chemistry to describe chemical compounds. For example, the molecular structure of water, which includes two hydrogen atoms and one oxygen atom, is commonly written:


Most modern word processors include a text formatting option that allows you to enter subscript or superscript text. HTML provides the <sub> tag for displaying subscript on webpages. If a text editor doesn't provide subscript formatting, you can shrink the font size of the subscript as a workaround. If you are working with plain text, the only option is to enter subscript characters on a separate line below the text.

Updated: May 14, 2015

Cite this definition:


TechTerms - The Tech Terms Computer Dictionary

This page contains a technical definition of Subscript. It explains in computing terminology what Subscript means and is one of many technical terms in the TechTerms dictionary.

All definitions on the TechTerms website are written to be technically accurate but also easy to understand. If you find this Subscript definition to be helpful, you can reference it using the citation links above. If you think a term should be updated or added to the TechTerms dictionary, please email TechTerms!

Subscribe to the TechTerms Newsletter to get featured terms and quizzes right in your inbox. You can choose to receive either a daily or weekly email.

Sign up for the free TechTerms Newsletter

How often would you like to receive an email?

You can unsubscribe at any time.
Questions? Please contact us.