Convert between Bytes, KB, MB, GB, TB, and PB. Supports binary (1024) and decimal (1000).
Binary vs. Decimal: The Source of Confusion
| Unit | Decimal (SI) | Binary (IEC) | Difference |
|---|
| KB / KiB | 1,000 bytes | 1,024 bytes | 2.4% |
| MB / MiB | 1,000,000 | 1,048,576 | 4.9% |
| GB / GiB | 1,000,000,000 | 1,073,741,824 | 7.4% |
| TB / TiB | 1,000,000,000,000 | 1,099,511,627,776 | 10.0% |
| PB / PiB | 1015 | 250 | 12.6% |
Why Your Hard Drive Seems Smaller
A "500 GB" hard drive contains 500,000,000,000 bytes (decimal marketing). Windows reports size in binary β that's 465.66 GiB. You didn't lose 35 GB. Two measurement systems are fighting over the same label. macOS switched to decimal display in 2009, so a 500 GB drive shows 500 GB on a Mac.
Real-World File Sizes
| Content | Typical Size |
|---|
| Plain text email (no attachments) | 5β50 KB |
| Smartphone photo (12 MP JPEG) | 3β5 MB |
| Raw photo (full-frame mirrorless) | 25β60 MB |
| 4K movie (2 hours, compressed) | 15β30 GB |
| AAA video game (2024) | 50β150 GB |
| Full human genome sequence | ~100 GB uncompressed |
How to Use This Byte Converter
Enter a value and select its unit (bytes, KB, MB, GB, TB, PB). The calculator converts to all other units in both binary (KiB, MiB, GiB) and decimal (KB, MB, GB) systems.
Formula & How It Works
Decimal: 1 KB = 1,000 bytes, 1 MB = 1,000,000. Binary: 1 KiB = 1,024 bytes, 1 MiB = 1,048,576. The difference grows with scale: 1 TB = 931 GiB.
Calculation Example
500 GB hard drive: 500,000,000,000 bytes = 465.66 GiB. That is why a "500 GB" drive shows ~465 GB in Windows (which uses binary).
Expert Tips
Storage manufacturers use decimal (1 GB = 10βΉ bytes), while operating systems use binary (1 GB = 2Β³β° bytes). This is why you always see less space than advertised. RAM is always measured in binary.