# “Order of magnitude” for changes in prefix

Order of magnitude usually denotes a change of a factor of 10. Is there a similar term for a change by a factor of 1000?

For example:

Kb -> Mb

Tb -> Gb

Edit: I agree that you can just say "three orders of magnitude" but I am wondering if there is a more concise or appropriate term.

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For a "math-literate" audience, "Mb is greater than Kb by three orders of magnitude" is about as concise as it gets. For the rest of the world, you just have to say "Mb is a thousand times greater than Kb". – FumbleFingers Dec 22 '11 at 16:52
Of course 1Mb is actually 1024Mb, not 1000Mb. But "order of magnitude" in informal English tends to imply some level of approximation. – slim Dec 22 '11 at 17:03
While I agree that "thousandfold" is probably the clearest answer, I've also seen a factor of 1000 referred to as an "engineering order of magnitude", coming from the ubiquitous engineering use of SI prefixes which, as you note, go up or down by factors of 1000. – Erik Johnson Dec 22 '11 at 17:38
@slim You wanted to say "Of course 1Gb (!!!) is actually 1024Mb", didn't you? – Stephen Dec 22 '11 at 19:09
"Of course 1Mb is actually 1024Mb, not 1000Mb." Hello, what! I would be thoroughly glad to get 1000Mb for 1Mb, better if it's 1024. – Kris Dec 23 '11 at 10:48

Consider thousandfold. The example in wiktionary is:

The changes to the algorithm resulted in a thousandfold increase in efficiency, earning the engineer a small brass plaque.

wiktionary also shows a plural, thousandfolds, but for purposes of approximation, go with thousandsfold instead. Example: "There was a thousandsfold increase in consumption when they added ingredient X."

Edit: Note that ngrams shows little use of either of thousandfolds or thousandsfold by comparison with thousandfold. Here are some examples of use of thousandsfold evinced in google-books references:

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+1 Also twofold, sevenfold, tenfold, hundredfold, other numbers. – slim Dec 22 '11 at 17:04
-1 for thousandsfold. I'll reverse the downvote if you correct that! – FumbleFingers Dec 22 '11 at 19:19
@FumbleFingers - I've added comments re "thousandsfold" usage in several books. Have I misunderstood? – jwpat7 Dec 22 '11 at 19:54
The original publication date of "Across Western Waves: ..." was 1848 – jwpat7 Dec 22 '11 at 20:07
@jwpat7: Not any more, I guess. Even in the explicit case several thousandfold where plural definitely applies, including that "s" is below the radar in NGrams. You think it's okay - but I don't, and apparently the majority are with me. But ELU is nothing if not democratic, and you don't need my vote to be winning here (though I imagine it's more for thousandfold than for the non-standard plural). – FumbleFingers Dec 22 '11 at 21:32

"Three orders of magnitude".

Or less precisely "orders of magnitude".

Or, still imprecise, and for larger orders "several orders of magnitude".

Note that for many people who are not mathematically literate an "order of magnitude" just means "a lot".

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+1 for 'a lot'. – Mitch Dec 22 '11 at 16:56
It's not just interpretation by readers who aren't mathematically literate; it's that the phrase is often used metaphorically. That's an order of magnitude better might mean a lot depending on the context. This use seems reasonably common, for example, in news, where phrases like his changes of mind are greater than Mr Romney's by an order of magnitude appear, and even science-related articles say things like roughly an order of magnitude. – aedia λ Dec 22 '11 at 17:11

Could we say a megabyte is a kilobyte grand? My coinage, though.

As an aside,
New IEC Standard
megabyte (decimal) MB (=) 1000 kilobytes

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