Units of measurement in DU Meter

DU Meter follows certain conventions for reporting data amount and data transfer rate. Although several standards exist for prefixes and abbreviations used in telecommunications industry, these standards are largely ignored and abbreviations are often used incorrectly, which leads to misunderstanding and confusion. This page documents conventions and abbreviations used in DU Meter.

DU Meter has a configuration option that affects reporting. When "Follow IEC 60027-2 (KiB, MiB)" option is enabled, DU Meter strictly follows SI and IEC 60027-2 standards. Since most users are not accustomed to these abbreviations, this mode is disabled by default.

Data amount

DU Meter reports data transfer totals in bytes. Each byte consists of 8 bits, which is basic unit of information. The following table documents abbreviations and multipliers used in DU Meter:

Multiplier Normal mode IEC 60027-2
1024 KB KiB
1024*1024 MB MiB
102410241024 GB GiB
102410241024*1024 TB TiB
10241024102410241024 PB PiB

Data transfer rate units

Data transfer speeds (bitrates) are most often quoted in 'bits per second', or multiples of that unit. This is a standard practice in the telecommunications industry. However, some users prefer 'bytes per second', which are sometimes more handy, since file sizes are always reported in bytes and not bits. DU Meter uses 'bits per second' units by default, but the alternative 'bytes per second' mode can be chosen in DU Meter options if preferred.

Even though data amount multipliers are binary (1024 bytes in one kilobyte), data transfer rate multipliers are decimal when bits are used (1000 bits per second is one kilobit per second) and binary when bytes are used (1024 bytes per second is one kilobyte per second). This notion is confusing, but universally accepted, therefore DU Meter follows it.

Data transfer rate abbreviations in bits per second mode:

Multiplier Normal mode SI
1 bps bit/s
1000 kbps kbit/s
1000*1000 Mbps Mbit/s
100010001000 Gbps Gbit/s
100010001000*1000 Tbps Tbit/s
10001000100010001000 Pbps Pbit/s

Data transfer rate abbreviations in bytes per second mode:

Multiplier Normal mode IEC 60027-2
1 B/s B/s
1024 KB/s KiB/s
1024*1024 MB/s MiB/s
102410241024 GB/s GiB/s
102410241024*1024 TB/s TiB/s
10241024102410241024 PB/s PiB/s

Reference

  1. Prefixes for binary multiples (NIST Reference)
  2. "byte" in Wikipedia
  3. "bitrate" in Wikipedia