Data Storage Converter
Convert digital data storage, file sizes, and memory capacities between bits, bytes, decimal SI standards (1000-based), and binary IEC units (1024-based).
1 GB = 0.931323 GiB
Common Conversions
Decimal SI vs. Binary IEC Standards
In computing, two conflicting multiplier systems have historically shared similar names. International standard organizations (IEEE, IEC, ISO, and BIPM) formally resolved this ambiguity by establishing distinct prefixes:
1. Decimal SI Standards (1,000-based)
Uses traditional metric powers of 10:
- 1 kB = 1,000 Bytes (10³)
- 1 MB = 1,000,000 Bytes (10&sup6;)
- 1 GB = 1,000,000,000 Bytes (10&sup9;)
- 1 TB = 1,000,000,000,000 Bytes (10¹²)
Adopted by hard drive/SSD manufacturers, telecommunications, networking, and macOS.
2. Binary IEC Standards (1,024-based)
Uses true binary powers of 2 (2¹° = 1,024):
- 1 KiB (Kibibyte) = 1,024 Bytes (2¹°)
- 1 MiB (Mebibyte) = 1,048,576 Bytes (2²°)
- 1 GiB (Gibibyte) = 1,073,741,824 Bytes (2³°)
- 1 TiB (Tebibyte) = 1,099,511,627,776 Bytes (2&sup4;°)
Used in computer RAM architectures, CPU caches, and Windows OS file reporting (though Windows often ambiguously labels GiB as "GB").
Why Does a 1 TB Drive Show 931 GB in Windows?
A 1 TB hard drive contains exactly 1,000,000,000,000 bytes (decimal SI). When plugged into a Windows machine, the operating system divides that byte count by 1,024³ (1,073,741,824) to compute binary gibibytes:
Windows displays this value labeled as "931 GB", causing the false impression that 69 GB of space is missing. In reality, zero bytes are lost; it is purely a prefix mismatch.
Official Data Storage Reference Table
| Unit | Symbol | Standard | Exact Bytes |
|---|---|---|---|
| Bit | bit | Binary Unit | 0.125 B (1/8 Byte) |
| Byte | B | Base Unit | 1 Byte (8 bits) |
| Kilobyte | kB | Decimal SI | 1,000 B |
| Kibibyte | KiB | Binary IEC | 1,024 B |
| Megabyte | MB | Decimal SI | 1,000,000 B |
| Mebibyte | MiB | Binary IEC | 1,048,576 B |
| Gigabyte | GB | Decimal SI | 1,000,000,000 B |
| Gibibyte | GiB | Binary IEC | 1,073,741,824 B |
| Terabyte | TB | Decimal SI | 1,000,000,000,000 B |
| Tebibyte | TiB | Binary IEC | 1,099,511,627,776 B |
Common Worked Examples
Example 1: Convert 1 Gigabyte (GB) to Gibibytes (GiB)
1,000,000,000 B ÷ 1,073,741,824 B/GiB = 0.931323 GiB.
Example 2: Convert 1 Megabyte (MB) to Kilobytes (kB)
1,000,000 B ÷ 1,000 B/kB = 1,000 kB.