Data Storage Converter
Convert between bits, bytes, kilobytes, megabytes, gigabytes, terabytes, and binary units. Understand the difference between KB and KiB.
Quick Presets
Decimal Units (SI)
Base 1000 - Used by storage manufacturers
Binary Units (IEC)
Base 1024 - Used by operating systems
KB vs KiB: What is the Difference?
The difference between KB (kilobyte) and KiB (kibibyte) comes down to how we count bytes:
Decimal (SI) - KB, MB, GB
- 1 KB = 1,000 bytes
- 1 MB = 1,000,000 bytes
- 1 GB = 1,000,000,000 bytes
Used by: Hard drive manufacturers, network speeds
Binary (IEC) - KiB, MiB, GiB
- 1 KiB = 1,024 bytes
- 1 MiB = 1,048,576 bytes
- 1 GiB = 1,073,741,824 bytes
Used by: Operating systems, RAM specifications
Why does this matter? When you buy a 500 GB hard drive, the manufacturer uses decimal units (500,000,000,000 bytes). But your operating system displays storage in binary units, showing approximately 465 GiB. This is why your new drive appears to have less space than advertised - it is the same amount of storage, just measured differently.
Common Storage Sizes
| Item | Typical Size | In Bytes |
|---|---|---|
| Text email | ~10 KB | 10,000 bytes |
| MP3 song (4 min) | ~4 MB | 4,000,000 bytes |
| High-res photo | ~5 MB | 5,000,000 bytes |
| HD movie (2 hours) | ~4 GB | 4,000,000,000 bytes |
| 4K movie (2 hours) | ~20 GB | 20,000,000,000 bytes |
| Smartphone storage | 128-512 GB | 128-512 billion bytes |
About Data Storage Units
Understanding Bits and Bytes
A bit is the smallest unit of digital information - it can be either 0 or 1. A byte consists of 8 bits and can represent 256 different values (2^8). Bytes are the fundamental building blocks of all digital storage.
The History of KB vs KiB
In the early days of computing, storage professionals used "kilobyte" to mean 1,024 bytes because computers work in binary (powers of 2). However, the metric system defines "kilo" as exactly 1,000. This created confusion.
In 1998, the International Electrotechnical Commission (IEC) introduced new binary prefixes: kibi (Ki), mebi (Mi), gibi (Gi), etc. These unambiguously refer to powers of 1024, while the traditional prefixes (K, M, G) strictly mean powers of 1000.
Practical Applications
- Network speeds: Internet speeds are measured in bits per second (Mbps, Gbps). To convert to bytes, divide by 8.
- Storage devices: Manufacturers use decimal units (GB, TB) for marketing. Your OS shows binary units (GiB, TiB).
- RAM: Memory is always measured in binary units because of how computers address memory.
- File sizes: Most operating systems display file sizes in binary units with decimal labels (confusingly calling GiB as GB).