Wolfram alpha thinks there are 1000 bytes in a kilobyte apparently

Wolfram Alpha is right. The use of "kB" to refer to 1024 bytes is incorrect and results from historical issues involving hardware addressing and RAM.

I discuss this in some more detail on the tarsnap (beta testing) website in explaining why I charge $0.30 per GB-month of storage instead or $0.30 per GiB-month of storage: https://beta.tarsnap.com/GB-why.html

I think I caught a discussion elsewhere about this; but Wolfram gets it right when using the SI notation:

http://www05.wolframalpha.com/input/?i=1000000+MiB+in+GiB

Hard drive makers also prefer the SI definition, as it makes the sizes seem larger.

When I first heard of 'Kibibytes' and 'KiB', I thought it was silly.

But each time there's confusion, the pedantry looks a little better.

And certainly when writing documentation and user interfaces, the KiB/MiB/GiB/TiB/PiB distinctions should be made clear.