With miles, there are no SI prefixes, so, you just write "every 3k/10k miles".

With kilometres, there's already an SI prefix present.

What's the sane way to write, say, "5000 / 16'000 km" in a shorter form, without all the zeros?

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    The sane way to write it is 5000 or 16000 km. If you want to look like a dork, of course you're free to use Mm, but nobody will understand you. They'll probably think you've just got the munchies... – R.. GitHub STOP HELPING ICE Jun 22 '13 at 17:23
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    This question appears to be off-topic because it is about units of measure. – Brian Knoblauch Jun 28 '13 at 15:27

Yes you can apply all SI prefixes to meters. So a megameter would be one million meters or 1000 kilometers.

Gigameter is 1000 megameters.
Terameter is 1000 gigameters.
Petameter is 1000 terameters etc.

Gigameter and higher are usually only used in the context of space and astronomy because in normal contexts it is impossible to visualize or relate those distances. People don't simplify down 120,000 km to 120 Mm because of tradition and because their odometer reads in kilometres, and also because it is hard to relate to a megameter.


Yes, there is such a thing as a Megameter. And no, you shouldn't use it unless you're sure people know what you're talking about. Grammatically, the rule is to write 16000km as "sixteen thousand kilometers". not exactly shorter, but much easier to read.

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