Rather than use the barred M, however, accounting went with MM as an abbreviation for a million. For example, 1MM equals 1 million, $34MM equals $34 million and so on.

If we wanted to denote millions, we would show that as MM. For this, we should credit the Romans. M is the Roman numeral for thousand and MM is meant to convey one thousand-thousand — or million. To take it further; one billion would be shown as $1MMM or one-thousand million.

What is MM? In finance and accounting, MM (or lowercase “mm”) commonly denotes that the units of figures presented are in millions. The Roman numeral M denotes thousands. In this context, MM is the same as writing “M multiplied by M,” which is equal to “1,000 times 1,000,” which equals 1,000,000 (one million).

The correct abbreviation to use while writing million is mil. To write 1 million is an abbreviated form; we write as 1 mil. How do you write 1.5 mil? 1.5 mil is written as 1,500,000 in numeric form.