128 kilobytes or 128 kilobyte? 128 kBs or 128 kB?

Question

I know that it is 128 Euro and 128 apples.

I think it is 128 kilobytes, megabytes, gigabytes. Or is it 128 kilobyte, megabyte, gigabyte?

If plural is correct, I should really use 128 kBs, MBs, GBs. That looks unfamiliar.

Which is correct, plural or singular?

Thanks :)

Answer 1

Both. You use "128 kB" and "128 kilobytes" just as you use "ten seconds" and 10s. Convention in most of the sciences is to pluralize when you write out the long form and also when you say it verbally, but to omit the "s" when you write the unit shorthand.

Answer 2

The word is plural, but the abbreviation doesn't have the s on the end. It is a conundrum.

Answer 3

Units of measurement don't ever use plural in their abbreviation. You never say "100 ms" for one hundred meters. So, you use 128 kilobytes, and 128 KB (that is, assuming B is really the abbreviation for Bytes)

Answer 4

If you had an s at the end of kB (ie kBs) it would look too much like kB/s or kBps which is a speed not size.