Express thousands of dollars using a comma.


Express millions and billions of dollars this way.

$3 million
$1.2 billion

Do not use a hyphen to join a number and words such as “million” or “billion,” even when used as a unit modifier.

$4 million prize
$200 billion budget

In technical reports and papers, use a dollar sign to express costs less than $1.

$0.06 per kilowatt-hour