Convert between bits, bytes, KB, MB, GB, TB, PB, and binary units (KiB, MiB, GiB) instantly.
This tool converts between ten data size units spanning both decimal (SI) and binary (IEC) standards. The input is first converted to bytes, then converted to the target unit. Decimal units (KB, MB, GB, TB, PB) use powers of 1,000, while binary units (KiB, MiB, GiB) use powers of 1,024. The distinction matters because a 1 TB drive (decimal) holds about 931 GiB (binary).
| Decimal (SI) | Bytes | Binary (IEC) | Bytes |
|---|---|---|---|
| 1 KB (Kilobyte) | 1,000 | 1 KiB (Kibibyte) | 1,024 |
| 1 MB (Megabyte) | 1,000,000 | 1 MiB (Mebibyte) | 1,048,576 |
| 1 GB (Gigabyte) | 1,000,000,000 | 1 GiB (Gibibyte) | 1,073,741,824 |
| 1 TB (Terabyte) | 1,000,000,000,000 | — | — |
| 1 PB (Petabyte) | 1,000,000,000,000,000 | — | — |
Hard drive manufacturers use decimal units (1 TB = 1,000,000,000,000 bytes), while operating systems like Windows display sizes in binary units (calling them GB/TB but actually meaning GiB/TiB). This is why a 1 TB hard drive shows as roughly 931 GB in Windows. Understanding this distinction helps avoid confusion when buying storage or managing files.