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Convert terabytes to gigabytes
Type a number and see it converted as you type. 1 terabyte = 1,000 gigabytes, so the conversion is simply × 1,000.
The formula
gigabytes = terabytes × 1,000
terabytes to gigabytes — quick reference
| terabytes (TB) | gigabytes (GB) |
|---|---|
| 1 | 1,000 |
| 2 | 2,000 |
| 3 | 3,000 |
| 4 | 4,000 |
| 5 | 5,000 |
| 10 | 10,000 |
| 15 | 15,000 |
| 20 | 20,000 |
| 25 | 25,000 |
| 50 | 50,000 |
| 75 | 75,000 |
| 100 | 100,000 |
| 250 | 250,000 |
| 500 | 500,000 |
| 1,000 | 1,000,000 |
A 1 TB drive showing 931 GB has lost nothing
The number on the box is decimal: one terabyte is 1,000,000,000,000 bytes, and drive manufacturers have used that definition for decades. Windows divides the same byte count by 1,024 three times and prints the result as "GB", producing 931. Every byte paid for is present on the platter; two conventions are simply sharing one label.
This has been settled for years rather than being a rounding quirk — litigation in the United States ended with manufacturers adding a footnote, not changing the figure. macOS and Linux switched to decimal reporting long ago, which is why the same external drive reads 1 TB on a Mac and 931 GB on a Windows machine plugged in minutes later.
What is genuinely missing is a far smaller number
Formatting does consume real capacity, but nothing like the gap above. The filesystem’s tables, journal and reserved blocks account for a low single-digit percentage, a few gigabytes on a terabyte. A factory recovery partition on a pre-built machine takes a slice of its own, typically 10 to 25 GB, and it is hidden from the usual capacity display.
This tool converts decimal, so 1 TB gives 1,000 GB. To predict what Explorer will show instead, multiply by 0.931; to test whether a drive is actually short, compare raw byte counts rather than the friendly figures. Leave real free space as well — SSDs slow markedly once they run close to full.
Questions
How many gigabytes are in 1 terabyte?
1 terabyte = 1,000 gigabytes. To convert any amount, multiply by 1,000.
What is the formula to convert terabytes to gigabytes?
gigabytes = terabytes × 1,000. That is exactly what the calculator above does, so you can check its working.
Is the conversion exact?
It depends on what you mean by "kilo". This tool uses the decimal SI convention (1 KB = 1000 bytes), the one storage manufacturers use. Operating systems often use 1024 instead, which is why a drive reports less space than the box promises.
Updated 2026-07-20. The conversion runs in your browser — nothing is uploaded.