When to Hyphenate Numbers

Knowing when to hyphenate numbers is important because the correct use of the hyphen helps your reader to understand which numbers are part of a given adjective and avoids any ambiguity.

Let’s look at the example on the left.

Is the guy working twenty shifts that are each four hours long, twenty-four shifts that are each an hour long? Or shifts that last twenty-four hours in total?

As you can see, where you place the hyphen in the number can make a significant difference to the meaning of the sentence.If you are struggling to format text correctly and address any errors in your writing, take a look at our proofreading services.

Hyphenating Numbers: The Rules

1. You should always hyphenate numbers when you are describing compound numbers between 21 and 99 (except 30, 40, 50, 60, 70, 80 and 90). A compound number is any number that consists of two words; for example, eighty-eight, twenty-two, forty-nine.
2. Numbers higher than 99 do not need a hyphen.

Hyphenating Numbers: Examples

The bingo caller pulled a ball from the machine and announced: “Two little ducks, twenty-two.”

There were over one hundred people in line for the concert.

A total of two hundred and fifty-five people participated in the survey.

A one hundred million dollar profit is not such a big deal when you made two hundred and eighty-six million dollars the year before.

I haven’t seen Gerald since nineteen forty-five.

I was shocked to see that there were three hundred chickens living in the barn.

24,624,678 (24,624,678.5 (twenty-four million, six hundred twenty-four thousand, six hundred seventy-eight and five tenths).

One more thing…

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