How many is a zillion?

1 million = 1,000,000.

1 billion = 1,000,000,000 or 1,000,000,000,000 depending on if using the long or short scale.

How many is a zillion?

Although Wikipedia redirects "Zillion" to "Indefinite and Fictitious Numbers," are there expert definitions or defining professional usages of the word? The same article also describes how "forty" started out as an indefinite large number but now has a fairly precise meaning.

Solution 1:

According to the OED it is a very large but indefinite number, clearly, from the examples, of WW2 vintage.

Etymology: < Z n. + million adj. and n.

slang (chiefly U.S.). A very large but indefinite number.

1944 D. Runyon Runyon à la Carte (1946) 165, I love him a zillion dollars' worth.

1947 Esquire May 40/2 Faithful to their zillions of fans.

1976 National Observer (U.S.) 10 Jan. 10/4 A zillion or so years ago, while I was a student nurse.

1976 J. Crosby Snake (1977) xvii. 93 She was going to break the story to her zillion readers.

1983 Sunday Tel. 9 Oct. 20/2 Broken Hill Proprietary..is Australia's biggest company and a zillion times bigger than his own.

1984 Guardian 29 Oct. 9/2 The whiff of news managers at work, rather than an urge to hear about British Telecom's zillion-pound share sale from the horse's mouth, took me to BT's big press conference on Friday.