What’s the Difference Between a Billion and a Million, Anyway?

The transatlantic number confusion continues.

by Ben Sullivan
Oct 14 2016, 12:50pm

Image: Tom Hall/Flickr

How much is a billion? Is it a million million or is it a thousand million? And what about a trillion? This seems to be a confusing matter, if you're British at least.

This blog is the offspring of a stressful few days at Motherboard UK last month. The fiasco started when the European Space Agency released the initial data from its Gaia star-mapping mission. "Gaia has pinned down the precise position on the sky and the brightness of 1142 million stars," proclaimed a press statement.

Well bloody hell, I pondered. How much is 1142 million?

Of course, the answer is 1.142 billion. I should never have doubted myself. But it was just so weird seeing 1.142 billion written down as 1142 million. Who does that? This led us onto the conversation of what exactly constitutes a billion. In proper British English, a billion was a million million until 1975 when British Chancellor Denis Healey announced that the UK would adopt the US billion, which had always been a thousand million. A trillion, in British, used to mean a million million million, but now, like a billion, means a million million. We could go on to quadrillions and quintillions, but that's a whole other story.

In an original headline for the Gaia article, we used 1,142 million, but Editor-in-Chief Derek Mead simply wasn't having any of it.

"Darn hootin' limeys," Mead was reportedly heard muttering. The headline was subsequently changed to reflect the figure in terms of billions (not thousands) of millions. Are the yanks just as confused as us?

My efforts to reach out to ESA didn't go as planned, either. The space agency's press office seemed outright offended at my confusion. Below is the correspondence between the ESA press office and myself:

Image: Ben Sullivan

After a few befuddling back and forths, ESA finally admitted, "We just think that mentioning millions in x1000s is understandable for most people. If they understand a million, they will understand a quantity of one thousand of those millions."


Next, a Twitter poll ordered by former Motherboard UK editor Victoria Turk showed only 52 percent of respondents knew the "correct" answer. Evidently, the issue wasn't as clear-cut as ESA made out. There was only one option left to take: ask a mathematician.

In Motherboard's long and arduous quest to reveal the truth behind this numerical nonsense, we reached out to the University of Oxford's very own lecturer in mathematics history, Dr. Chris Hollings. If anyone could explain this, surely he could. Right?

"I didn't know the answer to this myself, but it turns out that the [Oxford English Dictionary] addresses it directly—the relevant entry is attached," he told me.

Yes, even a lecturer in Mathematics and its History at the Mathematical Institute of the University of Oxford had to refer to a dictionary to give me an answer. So, here it is, once and for all, courtesy of Oxford University Press:

Image: Oxford University Press


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