How many gigabytes are in a terabyte? The simple answer is 1,000 GB. But Windows often shows a new 1 TB drive as about 931 GB. Why? Here's the difference between the two ways of counting.
Two ways of counting
| Decimal (manufacturers, OneDrive) | Binary (Windows) |
|---|---|
| 1 KB = 1,000 bytes | 1 KiB = 1,024 bytes |
| 1 MB = 1,000 KB | 1 MiB = 1,024 KiB |
| 1 GB = 1,000 MB | 1 GiB = 1,024 MiB |
| 1 TB = 1,000 GB | 1 TiB = 1,024 GiB |
Why does Windows show less?
A manufacturer sells a 1 TB drive as 1,000,000,000,000 bytes. Windows counts in powers of 1,024 but still calls it "GB". 1,000,000,000,000 bytes divided by 1,024³ is about 931 GB. Nothing is missing; it's just a different unit. On top of that, some space goes to recovery partitions and Windows itself.
Examples
- OneDrive: 1 TB of storage in Microsoft 365 is a little over 1,000 GB of files.
- An HD movie is roughly 4 to 8 GB, so 125 to 250 fit in 1 TB.
- A phone photo is roughly 3 to 5 MB, so over 200,000 fit in 1 TB.
Tip
Drive full? Read find large files in Windows 11, or turn on Files On-Demand in OneDrive. Also see change a user's OneDrive storage limit.
Read also
Find and delete large files in Windows 11 and 10: 5 ways
How to change the OneDrive storage of a single user
The 10 most useful features of OneDrive for work or school
Nederlandstalige versie: Hoeveel gigabytes zitten er in een terabyte?