SSD advertised size vs. operating systems reported size

Storage capacity can be measured in different units such as bytes and bits.

Summary

All computer data is stored in bits, using a binary format (that is, ones and zeros). Storage capacity can be measured in different units as shown in this table below with the most common ones:
 

Data MeasurementSize (Binary)Size (Decimal)
BitSingle Binary Digit (1 or 0) 
Byte8 bits 
Kilobyte (KB)1,024 Bytes1000
Megabyte (MB)1,024 Kilobytes10002
Gigabyte (GB)1,024 Megabytes10003
Terabyte (TB)1,024 Gigabytes10004
Petabyte (PB)1,024 Terabytes10005
Exabyte (EB)1,024 Petabytes10006
Zettabyte (ZB)1,024 Exabytes10007
Yottabyte (YB)1,024 Zettabytes10008



Since all computers are based on the binary system, these prefixes represent the base 2 amounts. Each level is an increment of 2 the 10th power, or 1024.


Hardware storage manufacturers measure 1GB as 1000 MB, while operating systems measure 1GB as 1024 MB. This can cause confusion, as you might think that the drive has less capacity than advertised.
Following are some of the most common sizes already converted:
40 GB ≈ 37,25 GB
60 GB ≈ 55,88 GB
80 GB ≈ 74,50 GB
120 GB ≈ 111,75 GB
160 GB ≈ 149,01 GB
200 GB ≈ 186,26 GB
240 GB ≈ 223,51 GB
320 GB ≈ 298,02 GB
400 GB ≈ 372,52 GB
500 GB ≈ 465 GB
640 GB ≈ 596 GB
720 GB ≈ 670,55 GB
1 TB ≈ 931,32 GB
2 TB ≈ 1.862,64 GB

Questions?
Contact Solidigm™ Customer Support

 

SSD advertised size vs. operating systems reported size