Byte / Data Size Converter
Bytes (B)—
Kilobytes (KB)—
Megabytes (MB)—
Gigabytes (GB)—
Terabytes (TB)—
Petabytes (PB)—
Free Data Size Converter
Convert between bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes. Supports both binary (1024-based) and decimal (1000-based) standards.
Binary vs Decimal
- Binary (IEC) — 1 KB = 1,024 bytes. Used by operating systems and most software (Windows, macOS, Linux).
- Decimal (SI) — 1 KB = 1,000 bytes. Used by hard drive manufacturers and network speeds.
This difference is why a "500 GB" hard drive shows as ~465 GB in your operating system — the drive uses decimal gigabytes while the OS uses binary.
Quick Reference
| Unit | Binary | Decimal |
|---|---|---|
| 1 KB | 1,024 B | 1,000 B |
| 1 MB | 1,048,576 B | 1,000,000 B |
| 1 GB | 1,073,741,824 B | 1,000,000,000 B |
| 1 TB | 1,099,511,627,776 B | 1,000,000,000,000 B |
Frequently Asked Questions
Why does my hard drive show less space than advertised?
Hard drive manufacturers use decimal (1 GB = 1,000,000,000 bytes), but your operating system uses binary (1 GB = 1,073,741,824 bytes). A "1 TB" drive has about 931 binary GB of usable space.