Data Storage Converter
Convert data sizes between decimal units (kB, MB, GB, TB, used by drive makers and networks) and binary units (KiB, MiB, GiB, TiB, used by many operating systems), so you can see why a "1 TB" drive shows about 931 GB.
- Bits
- –
- Bytes
- –
- Kilobytes (1,000 B)
- –
- Megabytes (1,000 kB)
- –
- Gigabytes (1,000 MB)
- –
- Terabytes (1,000 GB)
- –
- Kibibytes (1,024 B)
- –
- Mebibytes (1,024 KiB)
- –
- Gibibytes (1,024 MiB)
- –
- Tebibytes (1,024 GiB)
- –
How it is calculated
- Everything is converted through bytes. 1 byte = 8 bits.
- Decimal (SI) prefixes: 1 kB = 1,000 B; 1 MB = 1,000,000 B; 1 GB = 10⁹ B; 1 TB = 10¹² B
- Binary (IEC) prefixes: 1 KiB = 1,024 B; 1 MiB = 1,024² B; 1 GiB = 1,024³ B; 1 TiB = 1,024⁴ B
Worked example
| You enter | |
|---|---|
| Value | 1 |
| From | Terabytes (1,000 GB) (TB) |
| You get | |
| Bits | 8,000,000,000,000 bit |
| Bytes | 1,000,000,000,000 B |
| Kilobytes (1,000 B) | 1,000,000,000 kB |
| Megabytes (1,000 kB) | 1,000,000 MB |
| Gigabytes (1,000 MB) | 1,000 GB |
| Terabytes (1,000 GB) | 1 TB |
| Kibibytes (1,024 B) | 976,562,500 KiB |
| Mebibytes (1,024 KiB) | 953,674.316406 MiB |
| Gibibytes (1,024 MiB) | 931.322575 GiB |
| Tebibytes (1,024 GiB) | 0.909495 TiB |
1 TB equals 976,562,500 KiB, 953,674.316406 MiB, 931.322575 GiB.
Questions
Why does my 1 TB drive show about 931 GB?
The drive maker counts 1 TB as 10¹² bytes. Many operating systems divide by 1,024³ and still call the result "GB", which is really GiB: 10¹² ÷ 1,024³ = 931.32 GiB. No space is missing.
Sources and checks
Last checked: 12 October 2026. This calculator passes 5 automatic tests before every release.
Your numbers never leave your device: the calculation runs in your browser and nothing you type is sent or stored.
Conversions use exact legal definitions where they exist. Results are rounded for display. Results are estimates for information only and are not financial, tax or legal advice. Check important figures with a qualified professional before you act on them.