How to calculate real disk capacity

Use basic linux command-line utility to calculate real disk capacity.

Print real disk capacity for 32G hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 32G
29.8G

Print real disk capacity for 64G hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 64G 
59.6G

Print real disk capacity for 128G hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 128G 
119.2G

Print real disk capacity for 256G hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 256G 
238.4G

Print real disk capacity for 512G hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 512G 
476.8G

Print real disk capacity for 768G hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 768G 
715.2G

Print real disk capacity for 1T hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 1T
931.3G

Print real disk capacity for 2T hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 2T
1.8T

Print real disk capacity for 4T hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 4T
3.6T

Print real disk capacity for 5T hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 5T
4.5T

Print real disk capacity for 6T hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 6T
5.4T

Print real disk capacity for 8T hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 8T
7.2T

Print real disk capacity for 10T hard disk.

$ numfmt --from=si --to=iec --format="%.1f" --round=down 10T
9.0T