How much is a bilion?

Answer 1

In American English, it has always equated to a thousand million (i.e. 1,000,000,000).

In British English, a billion used to be equivalent to a million million (i.e. 1,000,000,000,000), while in British English has now adopted the American figure, though, so that a billion equals a thousand million in both varieties of English.

The same sort of change has taken place with the meaning of trillion. In British English, a trillion used to mean a million million million (i.e. 1,000,000,000,000,000,000). Nowadays, it's generally held to be equivalent to a million million, or 1,000 billion (1,000,000,000,000), as it is in American English.