Free Data Storage Converter
Convert data storage units instantly — bits, bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes. Free, symmetrical, no sign-up.
Exact Conversion Formula & Multipliers
Digital storage has two competing conventions, and this converter offers both: decimal (SI) prefixes where 1 kilobyte = 1,000 bytes, and binary (IEC) prefixes where 1 kibibyte = 1,024 bytes, since computers address memory in powers of two. Storage manufacturers typically advertise in decimal units while operating systems often report binary units, which is the well-known reason a '1 TB' drive shows less than 1,000 GB of usable space in Windows or macOS.
Practical Real-World Scenarios
- Buying storage devices: a drive marketed as '1 TB' (1,000,000,000,000 bytes decimal) shows as roughly 931 GiB in an operating system using binary units — not a manufacturing shortfall, but a unit mismatch.
- Network and internet speeds: internet service providers advertise speed in megabits per second (Mbps), while file sizes are shown in megabytes (MB) — an 8x difference that confuses download time estimates.
- Software development and IT: RAM and cache sizes are conventionally binary (1,024-based), while network transfer and disk marketing figures are conventionally decimal, requiring developers to track which convention applies where.
Historical & Technical Background
The kilobyte's ambiguity dates to early computing, when engineers reused the metric 'kilo' prefix loosely to mean 1,024 (2¹⁰) because it was close enough to 1,000 for casual use and matched binary addressing. As storage devices grew into gigabytes and terabytes, the compounding gap between 1,000-based and 1,024-based counting became large enough to matter commercially, prompting the International Electrotechnical Commission to introduce distinct binary prefixes (kibi-, mebi-, gibi-) in 1998 — though informal usage of 'KB' for either meaning persists today.
Precision & Accuracy Statement
Conversion factors use the exact defined values given in NIST Special Publication 811 and the BIPM SI Brochure wherever such a definition exists (for example 1 lb = 0.45359237 kg, 1 in = 2.54 cm, 1 US gal = 3.785411784 L, g₀ = 9.80665 m/s²); derived factors are computed from those definitions rather than copied as rounded figures. Results are calculated in double-precision floating point and shown to 10 significant digits, so the last digit can differ by one unit of rounding. The rounded figures in the text and tables above are for reading convenience.
How This Converter Works
Data storage uses powers of 1,000 (SI decimal) for storage marketing — where 1 KB = 1,000 bytes — but operating systems often use binary prefixes where 1 KiB = 1,024 bytes. Our converter offers both: decimal units (KB, MB, GB, TB, PB) and binary units (KiB, MiB, GiB, TiB).
Common Conversions
| Unit | Bytes | Common Use |
|---|---|---|
| 1 Byte (B) | 1 byte | Single character of text |
| 1 Kilobyte (KB) | 1,000 bytes | Short email or text document |
| 1 Megabyte (MB) | 1,000,000 bytes | 1–2 minute MP3 audio file |
| 1 Gigabyte (GB) | 1,000,000,000 bytes | ~250 photos or ~4 minutes of 4K video |
| 1 Terabyte (TB) | 1,000,000,000,000 bytes | External hard drive capacity |
| 1 Petabyte (PB) | 1,000,000,000,000,000 bytes | Large data centre storage |