> convert | bytes | data size <
// Convert between data size units: bits, bytes, KB, MB, GB, TB, PB
SI & IEC Standards
Support both SI (1000-based) and IEC (1024-based) unit standards. Toggle between them or view all at once.
All Units
Convert between bits, bytes, KB, KiB, MB, MiB, GB, GiB, TB, TiB, PB, and PiB simultaneously.
Bidirectional
Change any field and all others update instantly. 100% client-side, no server needed.
// ABOUT DATA SIZE UNITS
SI vs IEC Standards:
SI (International System of Units) uses powers of 1000: 1 KB = 1,000 bytes. IEC (International Electrotechnical Commission) uses powers of 1024: 1 KiB = 1,024 bytes. The IEEE 1541 standard recommends using IEC prefixes (KiB, MiB, GiB) for binary quantities.
Example:
1 GB = 1,000 MB (SI) = 953.67 MiB (IEC)
Common Use Cases:
- >Storage capacity calculations (disks use SI)
- >Memory size conversions (RAM uses binary/IEC)
- >Network bandwidth and transfer size estimation
- >Understanding disk vs advertised capacity differences
- >File size analysis and comparison
>> frequently asked questions
Q: What is the difference between KB and KiB?
A: KB (kilobyte) uses the SI standard where 1 KB = 1,000 bytes. KiB (kibibyte) uses the IEC binary standard where 1 KiB = 1,024 bytes. The difference grows larger with bigger units: 1 TB vs 1 TiB differs by about 10%.
Q: Why is 1024 used instead of 1000?
A: Computers operate in binary (base 2). Memory is addressed in powers of 2, making 1024 (2^10) a natural boundary. Historically, 'kilo' was used loosely for both 1000 and 1024, leading to the IEC introducing distinct binary prefixes (Ki, Mi, Gi) in 1998.
Q: What is the difference between SI and binary prefixes?
A: SI prefixes (kilo, mega, giga) are powers of 1000, used by disk manufacturers and networking. Binary prefixes (kibi, mebi, gibi) are powers of 1024, used for RAM and operating system file sizes. This mismatch is why a '1 TB' drive shows less than 1 TB in your OS.
Q: Which standard should I use?
A: Use SI (KB, MB, GB) for storage capacities, network speeds, and general communication. Use IEC (KiB, MiB, GiB) for precise binary quantities like RAM sizes, page sizes, and buffer allocations. When in doubt, specify which standard you mean.
Q: Why does my hard drive show less space than advertised?
A: Hard drive manufacturers use SI units (1 GB = 1,000,000,000 bytes), while operating systems typically display sizes in binary units (1 GiB = 1,073,741,824 bytes). A '500 GB' drive contains 500,000,000,000 bytes, which equals about 465.66 GiB.