SoFunction
Updated on 2025-04-14

Notes on hard disk capacity

Everyone always says that the system display capacity does not match the nominal capacity of the hard disk

Here are some detailed instructions:

In Windows system,

The basic unit of data is Byte,

That is what we often call bytes,

A Byte can store an English letter or half a Chinese character.

Since 1Byte is composed of 8bit binary numbers,

Therefore, the carry system in the system is also based on the binary system.

So in WINDOWS

1KB=2^10 B=1024B
1MB=2^10 KB=1024KB
1GB=2^10 MB=1024MB
1TB=2^10 GB=1024GB

However, the calculation capacity of hard disk manufacturers is based on decimal system as the standard

So the nominal capacity of the hard disk

1KB=10^3 B=1000B
1MB=10^3 KB=1000KB
1GB=10^3 MB=1000MB
1TB=10^3 GB=1000GB

Therefore, it is easy to calculate the capacity of the hard disk nominal capacity displayed in WINDOWS

12G=12*10^9B/2^30=11.2G
20G=20*10^9B/2^30=18.6G
30G=30*10^9B/2^30=27.9G
40G=40*10^9B/2^30=37.2G

The larger the capacity, the more it looks like it is "lossed"

In fact, it's just that different carry systems give hard disk manufacturers an opportunity to take advantage of loopholes.

It can make your hard drive capacity "up" very large, but it doesn't look that big :)