Why is Number Abbreviated as No?

Historical Origin

Latin Origin 

The abbreviation "No." comes from the Latin word "numero," which means "by the number" or "in number." In Latin, "numero" is the ablative case of the word "numerus," meaning "number." The abbreviation "No." was derived from the first two letters of "numero," following a common practice of abbreviating words by using the initial letters.

Adoption in English

English adopted the abbreviation "No." from Latin as a convenient shorthand for the word "number." This usage became widespread, particularly in contexts where space was limited, such as in lists, tables, or addresses.

Why Not "Nu." or "N."?

Consistency with Latin

The abbreviation "No." was chosen to remain consistent with the Latin origin. While "Nu." or "N." could logically be abbreviations for "number," the use of "No." honors the Latin tradition and was widely accepted before alternative forms could take hold.

Distinction from Other Abbreviations

Using "N." alone might have been confusing, as it could stand for other words, such as "North" or "Name." "No." is distinctive and clearly recognized as an abbreviation for "number."

Modern Usage

Common Applications

"No." is commonly used in many English-speaking countries, especially in contexts like:

➡️ Addresses: "123 Main St., Apt. No. 4"

➡️ Lists and Rankings: "No. 1 on the list"

➡️ Forms and Documents: "Please enter your employee No."

International Usage: 

While "No." is widely understood, other languages might use different abbreviations for "number." However, "No." is often recognized in global contexts due to its Latin roots and widespread use in English.

Need to learn more about the use cases with abbreviations? Have a look at this article discussing Architect Abbreviation. You may also like the background information from the debate - Is it Min or Mins in the Plural?

FAQ

Why isn’t "number" abbreviated as "Num."?

"No." was derived from the Latin "numero," and it became standard before alternative abbreviations like "Num." could take hold.

Is "No." still widely used?

Yes, "No." is still commonly used in English-speaking countries and is easily recognized as an abbreviation for "number."

Does any other language use "No." to mean "number"?

"No." is used in English, but similar forms can be found in other languages due to the influence of Latin. However, other languages may have their own abbreviations.

Can I use "No." in formal writing?

Yes, "No." is appropriate in both formal and informal contexts, especially in lists, addresses, and other places where space is limited.

How should "No." be written in plural form?

The plural form is "Nos." or "Nos," depending on style, and it stands for "Numbers." For example, "Nos. 2 and 3 were completed."