Grammar Blogger: 14-Year-Old Or 14 Years Old?

Which of the following examples is correct:
(1) He is a 14-year-old blogger.
(2) He is a 14 years old blogger.

Well, the answer is (1).

Explanation:
When modifying a person with his or her age, the compounded phrase is hyphenated: my six-year-old son. However, when the age comes after the person, we don't use a hyphen. My son is six years old. He is, however, a six-year-old.

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An easy way to remember when to use hyphens in age-related terms: if the word is year, hyphenate. If the word is years, do not. So you’d say The two-year-old kid wailed, but The kid, who is two years old, wants some ice cream.

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Hope this helps!