what is the correct abbreviation for millions, billions and trillions in a financial context?

I've found answers on the web but also got conflicting answers from financial professionals (coworkers).

In metric, you'd use M (mega) for million, G (giga) for billion and T (tera) for trillion. The only financial specific similar abbreviation I can find is MM for million (financial notation, according to wikipedia).

What's the AP style (or equivalent) abbreviation for billion and trillion in a financial context?

Bonus: where would I find this information?


I have seen million, billion, and trillion abbreviated as M, B, and T respectively. However, I would not bet that that is a standard abbreviation.

$3.1M settlement in Daniel McCormack priest sex abuse case for Chicago Archdiocese
Lawyers: $9M settlement for boy's cerebral palsy - Washington Times
JPMorgan reaches record $13B settlement with DOJ
Big win for BofA: Judge OKs $8.5B settlement with mortgage bondholders
China Now Owns a Record $1.317T of U.S. Government Debt


It certainly depends on your audience. I generally use $___MM, which was, and still is, often used by accountants and economists. Before "K" was adopted as the colloquial way of writing a thousand (i.e. $35k to mean $35,000), it was common to use "M" instead; "M" being the Roman Numeral for 1,000. As a result, "M" simply became shorthand for adding three zeros and thus "MM" became the shorthand for adding six zeros.


UK media tend to use m and bn for million and billion: "Grenier rejects £10m Newcastle switch", "Liberty Global buys Ziggo for €10bn". However, this usage is much less common in the US.


I have worked in equity markets for 20 years and poor abbreviations drive me crazy. Regretfully, until the USA goes metric there's going to continue to be problem with this.

Metric, engineering standards are useful:

CORRECT m = metre mm = millimetre

k = kilo (10^3, thousand) M = Mega (10^6, million) G = Giga (10^9, billion) T = Tera (10^12, trillion) P = Peta (10^15, quadrillion) E = Exa (10^15, ??)

In keeping with this I use: M = million B = billion T = trillion

etc...but it's not clear.

INCORRECT mm = very common. In many measures of materials..."million metric tonnes (tons)" is abbreviated to mmt. From that I see many analysts use mm to mean million. But it is a terrible abbreviation. I look forward to paying someone, some day, say $1mm. In response, I would cut 1 millimetre off a $1 bill and hand it to them... ;-)