Hard Drives & SSDs: Actual Formatted Capacity

Created on: June 3, 2013
Last updated: December 16, 2016

When formatted, all drives will be recognized as having less space available than the number of GB or TB designated in the product name. The reason for this is that operating systems consider 1GB to equal 1,024 bytes, while manufacturers consider 1GB to be 1,000 bytes. The larger the drive the more pronounced the difference will be.

Below is a listing of various drive sizes and the approximate size they should format to:


60 GB ~ 55.8 GB
100 GB ~ 93.1 GB
120 GB ~ 111.7 GB
160 GB ~ 149.0 GB
180 GB ~ 167.6 GB
200 GB ~ 186.3 GB
250 GB ~ 232.8 GB
300 GB ~ 279.4 GB
320 GB ~ 298.0 GB
400 GB ~ 372.5 GB
500 GB ~ 463.1 GB
750 GB ~ 698.5 GB
1.0 TB ~ 926.3 GB
1.5 TB ~ 1,397.0 GB
2.0 TB ~ 1,862.7 GB
3.0 TB ~ 2,794.0 GB
4.0 TB ~ 3,725.3 GB
5.0 TB ~ 4656.6 GB
6.0 TB ~ 5587.9 GB
8.0 TB ~ 7450.5 GB
10.0 TB ~ 9313.2 GB