File Size & Data Units
Understand the difference between binary (1024) and decimal (1000) unit calculations. See why your storage shows different sizes.
Size Converter
Results
Binary (Base 1024)
Used by operating systems, RAM
Decimal (Base 1000)
Used by storage manufacturers
Why the Difference?
This is why a "1 TB" hard drive shows as ~931 GB in your operating system.
Binary vs Decimal Comparison
| Unit | Binary (IEC) | Decimal (SI) | Difference |
|---|---|---|---|
| Kilobyte | 1,024 B (KiB) | 1,000 B (KB) | +2.4% |
| Megabyte | 1,048,576 B (MiB) | 1,000,000 B (MB) | +4.9% |
| Gigabyte | 1,073,741,824 B (GiB) | 1,000,000,000 B (GB) | +7.4% |
| Terabyte | 1,099,511,627,776 B (TiB) | 1,000,000,000,000 B (TB) | +10.0% |
Common Misconceptions
"My hard drive is missing space!" No, it's not. A 1 TB drive contains exactly 1,000,000,000,000 bytes. Your OS just displays it as ~931 GiB using binary units.
"KB means 1000 bytes" It depends! In most OS contexts, KB historically meant 1024 bytes. The IEC standard (KiB) was created to resolve this ambiguity.
"Storage manufacturers are cheating" They're using the correct SI (International System) prefixes. The confusion comes from historical computer conventions using powers of 2.