OS X Finder not showing correct file size - why and how "fix" it? I have a file that is 237153620 bytes long. Interestingly, Finder shows it as 237.2 MB. But we all know that's not true. Obviously it divides size in bytes with factor of 1000 (base 10) to get size in megabytes, instead of 1024 (base 2). Why is this so?

Some screenshots:





Edit: It was mentioned that switchDiskSizeBase could be used to switch between base 10 and base 2 file size, but it seems broken in El Capitan. (code sign failed when launching) Any idea on alternatives?
This is not a bug, so there is nothing to fix.  Apple (and pretty much every other computer company) moved over to base 10 to avoid confusion with the standards that we have with the metric system.

In metric:
    10 mm   = 1 centimeter
    1000 cm = 1 meter
    1000 m  = 1 kilometer


In base 2:
    1 byte  = 8 bits
    1 KB    = 1024 bytes
    1 MB    = 1024 kilobyte or 10242 = 1,048,576


So, in pretty much every other industry "Mega" meant 1 million of something, in computers it meant "1 million and 48 thousand, five hundred seventy six of something"

It wasn't until around 1998 that the IEC, IEEE and other standards organization wanted to address this ambiguity.  They clarified it by coming up with the "binary prefix" for the unit symbol.  

1 Kilobyte = 1,000 bytes.
1 Kibibyte = 1,024 bytes

 

This was done for the sole purpose of making things easier to understand as they related to computers.  

It's very easy to understand (using your file example) that you have a


0.237MB file
237.2KB file
2,272KB file


I don't have to break out a calculator to to do base 2 conversion.  It's very easy for me to understand that my 1/2 TB hard drive is 500GB and not 465.66GB