Ninety nine or Ninety-nine?

Ninety nine or ninety-nine?

In this article we show you how to write 99 in English words correctly.

In addition, we provide you with the grammar rule right away. 🙂

Regardless of where they appear in a number, hyphenate all compound numbers between 21 and 99 (not 30, 40, 50, 60, 70, 80, and 90) such as 99. In other words:

Hyphenate all numbers between twenty-one and ninety-nine, except those divisible by ten, even if the compound number is preceded or succeeded by numbers that do not require hyphens.

Thus, the correct spelling of 99 is ninety-nine (hyphenated).

Along the same lines:

• 99,000 = ninety-nine thousand (hyphenated).
• 99,000,000 = ninety-nine million (hyphenated).
• 99,000,000,000 = ninety-nine billion (hyphenated).

Ninety-nine or Ninety nine Spelling

It doesn’t matter which noun follows the adjective, the grammar rule explained above remains in place.

In the examples below the correct spelling is underlined.

Ninety nine years or ninety-nine years?
Ninety nine percent or ninety-nine percent?
Ninety nine hours or ninety-nine hours?

Frequently Asked Questions about Ninety Nine

Does ninety nine have a hyphen?

Yes, 99 has a hyphen and is spelled correctly as ninety-nine.

Do you hyphenate ninety nine?

Yes, you put a hyphen between ninety and nine: ninety-nine.

Does ninety nine need a hyphen?

As 99 is a compound number in between 21 and 99 it needs a hyphen; therefore writing 99 in full is ninety-nine.

In the table below we show you the correct spelling of some numbers succeeding and precededing 99:

Ninety ninth or Ninety-ninth?

In the following examples the correct spelling is underlined.

Ninety ninth part or ninety-ninth part?
Ninety ninth day or ninety-ninth day?
Ninety ninth hour or ninety-ninth hour?

Frequently Asked Questions about Ninety ninth

• Does ninety ninth have a hyphen? Yes, the ordinal number for 99 has a hyphen and is spelled correctly as ninety-ninth.
• Do you hyphenate ninety ninth? Yes, you put a hyphen between ninety and ninth: ninety-ninth.
• Does ninety ninth need a hyphen? 99 is a compound number in between 21 and 99 which needs a hyphen. Thus, writing 99th in full is ninety-ninth.

Ninety ninth or Ninety-nine?

As you already know, 99 as cardinal numeral is ninety-nine, and 99 as ordinal numeral is ninety-ninth.

Thus, the question in the subtitle above mixes two distinguished linguistic concepts and cannot be answered as such.

Observe that you can always check how to spell a number in full correctly using our converter below.

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Spelling: Ninety-nine

Summary

As explained by the hyphens-in-numbers rule, 99 = ninety-nine.

If you are happy with our information, then you may also be interested in our article twenty two or twenty-two.


We love to hear your feedback and answer any question about how to correctly write 99 you might have.

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– Article written by Mark, last updated on May 5th, 2023