Millions of Dollar or Millions of Dollars? Which is correct?

We say “millions of dollars” in English because we need the plural form of “dollar”. “Millions of dollar” is incorrect.  


I have millions of dollars in the bank 

That house costs hundreds of millions of dollars. 

In the first example, “millions” means some multiple of millions but we don’t know how much exactly. It could be 5,12, or 35 million but it is not one million or probably not more than one billion.    

Million, Dollar – Singular and Plural

To form the plural of million and dollar you should add an “s” like a regular plural noun.

Singular       Plural 

A dollar      some dollars

A million    some millions

Note that when you use a specific number with “million”, you do not use the “s”

Number with Dollar/Million

You use the regular plural with the dollar when you use specific numbers.

1 dollar

3 dollars

10 dollars

51,345 dollars

We do not use the plural “s” when we use the plural with million.

1 million

3 million

10 million

51,345 million

This rule for million is true regardless of whether we use million for money or in other contexts.

Hundreds of millions or hundreds of million

We use “hundreds of millions“ when we are being vague about the number.

I have hundreds of millions of books.

If you are using a specific number, you should drop the s in hundreds and millions.

I have exactly 5 hundred million books.