Data units
Converts bits, bytes, kilobytes, megabytes, gigabytes and terabytes — all 10 units recalculate simultaneously.
01
Converter
02
Orders of magnitude
orders of magnitude — what each size holds03
About data units
Data units measure the volume of digital information. The foundation is a bit — a single value of 0 or 1. Eight bits make a byte, and each subsequent unit is 1024 times larger than the previous.
That's why a 'gigabyte' on a hard drive package and in your operating system may differ: drive makers count in decimal thousands (1000), while OSes count in binary powers (1024).
Bit and byte
Basics1 bit = 0 or 1 · 1 byte = 8 bits
A bit is the minimal unit of information — physically one transistor. A byte is historically 'a character': 8 bits hold 256 values (0–255), enough for the English alphabet + control chars (ASCII).
1024 vs 1000
Binary vs SI1 KiB = 1 024 B · 1 kB = 1 000 B
Drive makers count in decimal thousands (1000): '1 TB' on the box = 10¹² bytes. Operating systems (Windows, Linux) count in binary powers (1024): '1 TiB' = 2⁴⁰ bytes. The gap grows: a 1 TB HDD shows up as ~931 GiB.
MB vs MiB
IEC 60027-2kB / MB / GB — SI · KiB / MiB / GiB — binary
The IEC 60027-2 (2000) standard introduced Ki, Mi, Gi prefixes for binary powers. In practice 'MB' and 'GB' are still used for both meanings — context decides: networks and drives use SI, memory uses binary.
A pixel is not a byte
Density1 RGB px = 3 B · 1 RGBA px = 4 B
A colour pixel takes 3 bytes (RGB) or 4 bytes (RGBA). A 1920×1080 raw image is ~6.2 MB, but JPEG compresses it to 300–800 KB. Video and audio are compressed too — otherwise a 4K movie would take terabytes.