What is the correct abbreviation for the words numbers and number?

  • Nos.
  • No.
  • Nos
  • No

Possible example usage:

  1. "Number of guests" where the word number is abbreviated
  2. "Numbers 10–15 are located in the top shelf."
  • 14
    The shortest expression is just #.
    – user13141
    Commented Sep 24, 2011 at 6:22
  • 3
    Sometimes there is a separate abbreviation for it... №
    – GEdgar
    Commented Sep 24, 2011 at 17:18
  • 2
    Does anyone find it odd when an abbreviation includes one or more letters that do not appear in the word being abbreviated?
    – user45992
    Commented Jun 13, 2013 at 13:07
  • 2
    @onomatomaniak The hash sign # is not a common or standard indication for 'number' in the UK. I do not know whether it is used in other English-speaking countries outside the US.
    – TrevorD
    Commented Aug 13, 2013 at 22:58
  • 3
    @user45992 I believe the 'o' in the abbreviation for 'number' comes from 'numero' (or a similar foreign word). lb & oz also include letters not in the corresponding English word. And where does the $ symbol come from - no 'S' in dollar.
    – TrevorD
    Commented Aug 13, 2013 at 23:01

4 Answers 4


It is highly unlikely that there is a global standard. It differs based on practice and the standards set by the relevant authorities (publishers and the like).

Ex: The Oxford Journal Instructions for Authors suggests (Sec. 2.3):

Abbreviations where the last letter of the singular word is not included take a full stop (vol., vols./ed., eds.). The abbreviation for number is no./nos. Abbreviated unit of measurements do not take a full stop (lb, mm, kg) and do not take a final 's' in the plural.

This is a suggestion from Cambridge Dictionary for use of no. as the abbreviation for number.

  • 1
    But no. is surely the abbreviation for "number" and nos. is the abbreviation for "numbers" in the Oxford Instructions. The "do not take a final 's' in the plural" only applies to lb, mm, kg, and so forth, and is irrelevant to this question. Commented Sep 24, 2011 at 17:59
  • 2
    Both Oxford and Cambridge links explain the usage for "Client No. 5" but I don't see an answer for the case "Number of guests". Anyone have an answer to that one? Commented Mar 13, 2012 at 17:15
  • Covered in that definition: "No. of guests."
    – The Nate
    Commented Oct 12, 2016 at 6:56

Cambridge dictionary only gives the abbreviation no. when number refers to a numeral, a position or identification, not a quantity, amount or calculation : http://dictionary.cambridge.org/dictionary/british/number_1

Therefore I understand "Number of guests" should not be abbreviated.

In other words, the ordinal number (e.g. No. 3, which indicates a position in an ordered list) is abbreviated, but the cardinal number (e.g. Number of guests, which indicates a numeric quantity) is not abbreviated.

  • 3
    I don't think the number need necessarily be an ordinal; what is important is that "no." is used with a number to identify something. The fact that two widgets have serial nos. 29432100 and 29432200 does not mean that there were 29,432,099 widgets produced before the first, nor that there were necessarily 99 widgets produced between them--it merely means that those numbers identify the widgets in question.
    – supercat
    Commented Aug 28, 2014 at 22:01

I use "num" or "nm" instead of "no" to avoid confusion with "yes/no" meaning -- especially in my computer programming variable names.

  • 3
    I use nof, which means "number of". Instead of nm_eggs_in_basket, nof_eggs_in_basket.
    – Pacerier
    Commented Mar 2, 2016 at 18:58
  • 4
    Indeed, using "no" can lead to confusion: test_validates_reference_no_format Commented Oct 3, 2018 at 14:06

Per Wikipedia — Numero sign, it's also possible to use " " and " No̲ ":

The numero sign or numero symbol, № (also represented as Nº, No̲, No. or no.), is a typographic abbreviation of the word number(s) indicating ordinal numeration, especially in names and titles.

For example, with the numero sign, the written long-form of the address "Number 22 Acacia Avenue" is shortened to "№ 22 Acacia Avenue", yet both forms are spoken long.

Though it doesn't seem to be common.

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