Tag Archives: hdd capacity less than mentioned on label

Why my 320 GB HDD is only 298 GB

Did you ever wonder that you had bought a 120 GB HDD but the computer showed it as a 111 GB HDD. And where did the rest of the space eventually disappear? Well nothing disappeared and even the manufacturer didnt make a fool of you.

This happens because there is a slight difference between the way the computer and the manufacturer calculate the HDD size.

One GB according to Computer Science Terminology

8bit = 1 Byte

1024 Bytes = 1 Kbyte

1024 KBytes=1MByte

1024 Mbytes=1GByte

One GB according to Manufacturers

8bit = 1 Byte

1000 Bytes = 1 Kbyte

1000 KBytes=1MByte

1000 Mbytes=1GByte

A we see that greater the hard drive size the larger is the number of missing GBs…

Theoretical Value Practically what we get
1 GB 0.931 GB
10 GB 9.31 GB
20 GB 18.62 GB
40 GB 37.25 GB
80 GB 74.50 GB
120 GB 111.75 GB
160 GB 149.01 GB
250 GB 232.83 GB
320 GB 298.02 GB
500 GB 465.66 GB

The manufacturers state that they call one GB as 109 and not 1024x1024x1024