Bit Rate - Prefixes

Prefixes

When quantifying large bit rates, SI prefixes (also known as Metric prefixes or Decimal prefixes) are used, thus:

1,000 bit/s	rate = 1 kbit/s (one kilobit or one thousand bits per second)
1,000,000 bit/s	rate = 1 Mbit/s (one megabit or one million bits per second)
1,000,000,000 bit/s	rate = 1 Gbit/s (one gigabit or one billion bits per second)

Binary prefixes have almost never been used for bit rates, although they may occasionally be seen when data rates are expressed in bytes per second (e.g. 1 kByte/s is sometimes interpreted as 1000 Byte/s, sometimes as 1024 Byte/s). A 1999 IEC standard (IEC 60027-2) specifies different abbreviations for Binary and Decimal (SI) prefixes (e.g. 1 kiB/s = 1024 Byte/s = 8192 bit/s, and 1 MiB/s = 1024 kiB/s), but these are still not very common in the literature, and therefore sometimes it is necessary to seek clarification of the units used in a particular context.