Storage units: decimal and binary
Choose the convention first
Decimal storage units use powers of 1,000: 1 kB = 1,000 bytes, 1 MB = 1,000,000 bytes and 1 GB = 1,000,000,000 bytes. Binary units use powers of 1,024: 1 KiB = 1,024 bytes, 1 MiB = 1,048,576 bytes and 1 GiB = 1,073,741,824 bytes. Use the selector to match the source you are comparing.
Worked comparison
A nominal 1 TB decimal drive contains 1,000,000,000,000 bytes. Expressed in binary units, that is approximately 931.323 GiB. The drive has not lost bytes merely because the display convention changed. Filesystems, recovery partitions and reserved space can separately reduce usable capacity.
Avoid common mistakes
A byte contains eight bits. This page converts storage amounts in bytes, not network speeds in bits per second. A 100 MB file is not a 100 Mb file. Results round for display; very large numbers are subject to JavaScript’s numeric precision limits. No files are uploaded or inspected. Definitions: NIST binary prefixes and SI prefixes.
Reference: NIST temperature; binary prefixes; conversion factors.