Billions can be confusing

While I had been aware of the different meaning of the term billion in English and German, recent discussions by users in a German-speaking online forum led me to look up the details. As is often the case, the full story is even more interesting.

Let’s start with the term million, for which no confusion arises. It is a shorthand to denote 1000 times 1000 or, using powers, 10⁶ units of something (people, currency, cars, …). Clearly, it is useful to have another shorthand for 1000 millions. However, this is where things become tricky. Whereas many languages adopted the French word milliard (Milliarde in German) for this purpose, the term billion (certainly easier to pronounce) became more popular in English. In particular, a billionaire in English is a Milliardär in German. However, billion was historically used with two different meanings (referred to as short scale and long scale), meaning either 10⁹ (1000 millions) or 10¹² (1 million millions). This goes back to a change of the definition by the French, see Wikipedia. In contrast, in most European languages, billion (Billion in German) refers exclusively to 10¹² (1 million millions, or 1000 milliards). Since billion is reserved for 10⁹ in English, another term (trillion) is needed for 10¹² (Billion in German).

Regarding the origin of the word billion, let me quote Wikipedia:

According to the Oxford English Dictionary, the word billion was formed in the 16th century (from million and the prefix bi-, “two”), meaning the second power of a million (1,000,000² = 10¹²).

While the two different definitions rarely cause confusion today in English, problems arise when translating to other languages. In principle, the rules are simple:

• English million = German Million (10⁶)
• English billion = German Milliarde (10⁹)
• English trillion = German Billion (10¹²)

All this causes quite some confusion among both professionals (in particular journalists) and amateurs. For example, I today saw journalists translate the liabilities of a company from $17 billion (original English article) first to $17 Milliarden in German and then to €17 Millionen, which would be only 1/1000 of the original amount. In fact, quite a few people seem to be under the incorrect impression that a billion US dollars is to be divided by 1000, whereas a billion Euros is not. This is of course nonsense: the necessary conversion is entirely due to different languages and has nothing to do with currencies.