Convert file and drive sizes between bytes, KB, MB, GB, TB and their binary GiB counterparts, plus bits
Windows counts in 1,024s but still labels the result GB, which is why a 1 TB drive shows up as 931 GB.
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The Data Storage Converter turns one size into sixteen units at once, and lays the decimal units (kB, MB, GB, counted in thousands) next to their binary twins (KiB, MiB, GiB, counted in 1,024s) so the gap between them is visible row by row. That gap is the whole reason this tool exists: a drive sold as 1 TB holds 1,000,000,000,000 bytes, which Windows divides by 1,024 three times and reports as 931 GB. For any size from a kilobyte up, the converter shows what Windows and macOS will each display for it. A bits section covers network speeds, so a 500 Mbps connection can be read as the 62.5 MB per second a download will actually reach at best.
The guide behind this tool
GB or GiB: Why a 1 TB Drive Shows Up as 931 GB
A terabyte drive holds 10¹² bytes, and Windows divides by 1,024 before calling it 931 GB. The 1999 standard that named the binary units, and why Macs disagree.
Type a size, either as a plain number or with its unit attached, such as 500 GB, 16 GiB or 100 Mbps.
If you typed a plain number, pick its unit from the "From" dropdown. A typed unit sets the dropdown for you.
Compare the decimal and binary columns row by row, and check the Windows and macOS readings to see the figure your file manager will show.
Click any result to copy the number without thousands separators.
Nothing is missing. The manufacturer counts a terabyte as 10¹² bytes, and Windows divides that by 1,024³ and labels the result GB, when by the standard it is 931 GiB. macOS has counted in powers of 1,000 since version 10.6, so the same drive shows as 1 TB there. Formatting takes a little more for the file system itself, which is why the free space on a new drive comes in slightly under even 931.
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