SI (decimal, 1000)
| Prefix | Symbol | Bytes | Shortform |
|---|---|---|---|
| kilobyte | kB | 10³ = 1 000 | 1 kB |
| megabyte | MB | 10⁶ = 1 000 000 | 1 MB |
| gigabyte | GB | 10⁹ = 1 000 000 000 | 1 GB |
| terabyte | TB | 10¹² = 1 × 10¹² | 1 TB |
| petabyte | PB | 10¹⁵ | 1 PB |
| exabyte | EB | 10¹⁸ | 1 EB |
IEC (binary, 1024)
| Prefix | Symbol | Bytes | SI equivalent |
|---|---|---|---|
| kibibyte | KiB | 2¹⁰ = 1 024 | 1 000 × 1.024 kB |
| mebibyte | MiB | 2²⁰ = 1 048 576 | ~ 1.049 MB |
| gibibyte | GiB | 2³⁰ = 1 073 741 824 | ~ 1.074 GB |
| tebibyte | TiB | 2⁴⁰ | ~ 1.1 TB |
| pebibyte | PiB | 2⁵⁰ | ~ 1.126 PB |
| exbibyte | EiB | 2⁶⁰ | ~ 1.153 EB |
Bits vs bytes
| 1 byte | 8 bits |
|---|---|
| 1 kbit/s | 1 000 bits/second (network) |
| 1 KiB/s | 1 024 bytes/second |
| Disk manufacturer marketing | uses SI (1 TB = 10¹² bytes) |
| OS reporting | often uses IEC (1 TiB = 2⁴⁰ bytes) |
Notes
- A 1 TB disk advertises 1 × 10¹² bytes. Your OS may display ~931 GiB — same bytes, different prefix.
- Network speeds are in bits/s (Mbps). File transfers in bytes/s (MB/s). Divide Mbps by 8 for MB/s.
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