It has happened to most of us. We acquire a new hard disk ( or maybe a flash drive) with mind-boggling storage capacity only to locate that it provides less space than what was described within the container. Angered, we commence cursing the manufacturer and each of our dealer meant for false advertising thinking that they should be sued designed for achieving this. Whats up, but have you ever considered how they carry on and try this again and again without getting into legal difficulty?


The answer is that they are not promoting it inaccurately in any way. Surprised? Let me explain.

A manufacturer considers 1 Megabyte for being 1000 Kilobytes, 1 Gb to be a thousand Megabytes, one particular Terabyte to be 1000 Gb and so on. This is certainly appropriate considering that kilo means 1000 and mega means 1000000 (10^6). However, computers calculate about on base 2 and to them, 1 megabyte is actually 1024 kilobytes, 1GB is 1024MB and 1 TB is definitely 1024GB. This difference in the method of computation is definitely responsible for this ” missing space”.

Let’s take on an example of a 500 GB hard disk.

From a computer’s point of view, 500GB is actually 500*1024*1024*1024 = 536870912000 bytes.

From a manufacturer’s point of view, the 500GB will have 500*1000*1000*1000 = 500000000000 bytes.

So, a hard drive that promises to have 500 GB storage space will actually display 465.66GB, 536870912000-500000000000 = 36870912000 bytes (34.34GB) less storage space when connected to a computer.


Space Promised

Displayed on a computer Difference




250GB 232.83GB 17.17GB
500GB 465.66GB 34.34GB


931.32GB 92.68GB
2TB 1862.64GB



Take a look at the table given above mentioned to see how much space is “lost” due to personal computers working on a base 2 system. As you can see, together with the increase in capability of the storage space device, there can be an increase in the lacking space.