As the amount of data the world produces grows ever larger, new words have been introduced to represent massive numbers.

After zetta (1021) and yotta (1024) were created in 1991, the General Conference on Weights and Measures (CGPM) has voted to introduce ronna (1027) and quetta (1030).


The world produces zettabytes of data every year, and is expected to reach a yottabyte a year in the next decade.

What to call the next step up has been a matter of debate for some years, with hellabyte and brontobyte used as unofficial terms by many.

But their symbols (h and b) are used in the metric system already, complicating their use in research papers.

Now, however, that Q and R are taken, every letter of the alphabet has been assigned to the metric system.

Metrologist Richard Brown, who proposed the new words, told Nature that we could create compound prefixes that use two symbols such as kiloquetta (kQ). “But I think probably we’re a long way away from having to worry about this,” he said.

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