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| {{for|disk drives|Data transfer rate (disk drive)}}
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| {{Use dmy dates|date=August 2012}}
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| {{bitrates}}
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| In [[telecommunications]] and [[computing]], '''bit rate''' (sometimes written '''bitrate''' or as a variable ''R''<ref>{{cite book |url = http://books.google.com/books?id=-kNn_p6WA38C&pg=PA21&dq=bit+%22rate+R%22#v=onepage&q=bit%20%22rate%20R%22&f=false |title=Data Communications and Computer Networks | first =Prakash C | last = Gupta |publisher=PHI Learning |year= 2006 |accessdate=2011-07-10}}</ref>) is the number of [[bit]]s that are conveyed or processed per unit of time.
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| The bit rate is [[:wiktionary:quantified|quantified]] using the [[Data rate units|bits per second]] ('''bit/s''' or '''bps''') unit, often in conjunction with an [[SI prefix]] such as [[kilo-]] (kbit/s or kbps), [[mega-]] (Mbit/s or Mbps), [[giga-]] (Gbit/s or Gbps) or [[tera-]] (Tbit/s or Tbps). Note that, unlike many other computer-related units, 1 kbit/s is traditionally defined as 1,000 bit/s, not 1,024 bit/s, etc., also before 1999 when SI prefixes were introduced for units of information in the standard [[IEC 60027-2]].<ref>{{cite web | author= International Electrotechnical Commission | title= Prefixes for binary multiples | url= http://www.iec.ch/si/binary.htm | date= 2007 | accessdate= 2014-02-04}}</ref> Uppercase K as in Kbit/s or Kbps should never be used.{{fact|date=February 2014}}
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| The symbol for "bits per second" is "bit/s" (not "bits/s", according to the [[SI unit symbols and values of quantities|writing style for SI units]]). In less formal contexts the abbreviations "b/s" or "bps" are sometimes used, though this risks confusion with "[[byte]]s per second" ("B/s", "Bps"), and the use of the abbreviation ''ps'' is also inconsistent with the [[International System of Units|SI]] symbol for [[picosecond]].
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| One byte per second (1 B/s) corresponds to 8 bit/s.
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| ==Protocol layers {{anchor |Bit rates at various protocol layers}}==
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| ===Gross bit rate===
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| In digital communication systems, the [[physical layer]] '''gross bitrate''',<ref name="Guimarães">{{cite book |url= http://books.google.com/books?id=x4jOplMbLx0C&pg=PA692&dq=gross+bit+rate#v=onepage&q=gross%20bit%20rate&f=false |title=Digital Transmission: A Simulation-Aided Introduction with VisSim/Comm | first =Dayan Adionel | last = Guimarães |publisher=Spinger |year=2009 |chapter=section 8.1.1.3 Gross Bit Rate and Information Rate |accessdate = 2011-07-10}}</ref> '''raw bitrate''',<ref name="Pahlavan">{{cite book |url=http://books.google.com/books?id=WOCrSSfxE-EC&pg=PA133&dq=%22raw+data+rate+is%22#v=onepage&q=%22raw%20data%20rate%20is%22&f=false |title=Networking Fundamentals |author=Kaveh Pahlavan, Prashant Krishnamurthy | publisher= John Wiley & Sons |year=2009 |accessdate=2011-07-10}}</ref> [[data signaling rate]],<ref>{{cite book |url= http://books.google.com/books?id=On_Hh23IXDUC&pg=PA135&dq=dictionary+%22data+signaling+rate%22#v=onepage&q&f=false |title= Network Dictionary |publisher= Javvin Technologies |year = 2007 |accessdate=2011-07-10}}</ref> '''gross data transfer rate'''<ref name="3G">{{cite book |url= http://books.google.com/books?id=RoJj0zw_pDMC&pg=PA277&dq=%22net+data+transmission+rate%22+%22gross+data+transmission+rate%22#v=onepage&q=%22net%20data%20transmission%20rate%22%20%22gross%20data%20transmission%20rate%22&f=false |title=3G wireless demystified | first1 =Lawrence | last1 = Harte | first2 = Roman | last2 = Kikta | first3 = Richard | last3 = Levine | publisher= McGraw-Hill Professional |year= 2002 |accessdate= 2011-07-10}}</ref> or '''uncoded transmission rate'''<ref name= "Pahlavan" /> (sometimes written as a variable ''R''<sub>b</sub><ref name="Guimarães"/><ref name="Pahlavan"/> or ''f''<sub>b</sub><ref>{{cite book |url=http://books.google.com/books?id=6Hd6WqsgKIMC&pg=SA4-PA30&dq=%22f+b+%3D%22++bps+%22digital+communication%22#v=onepage&q&f=false |title=Principles of Digital Communication |author=J.S. Chitode |publisher=Technical Publication |year=2008 |accessdate=2011-07-10}}</ref>) is the total number of physically transferred bits per second over a communication link, including useful data as well as protocol overhead.
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| In case of [[serial communication]]s, the gross bit rate is related to the bit transmission time <math>T_b</math>
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| as:
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| :<math>R_b = {1 \over T_b},</math>
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| The gross bit rate is related to, but should not be confused with, the [[symbol rate]] or modulation rate in [[baud]], symbols/s or pulses/s. Gross bit rate happens to equal "baud" ''only'' when there are two levels per symbol, representing 0 and 1 respectively, meaning that each symbol of a [[data transmission]] system carries exactly one bit of data; something not true for modern [[modem]] modulation systems and modern LANs, for example.<ref>
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| Lou Frenzel.
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| [http://electronicdesign.com/communications/what-s-difference-between-bit-rate-and-baud-rate "What’s The Difference Between Bit Rate And Baud Rate?"].
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| Electronic Design. 2012.
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| </ref>
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| For most [[line code]]s and [[modulation]] methods:
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| :Symbol rate ≤ Gross bit rate
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| More specifically, a line code (or [[baseband transmission]] scheme) representing the data using [[pulse-amplitude modulation]] with 2<sup>''N''</sup> different voltage levels, can transfer ''N'' bit/pulse. A [[digital modulation]] method (or [[passband transmission]] scheme) using 2<sup>''N''</sup> different symbols, for example 2<sup>''N''</sup> amplitudes, phases or frequencies, can transfer ''N'' bit/symbol. This results in:
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| :Gross bit rate = Symbol rate · ''N''
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| An exception from the above is some self-synchronizing line codes, for example [[Manchester coding]] and [[return-to-zero]] (RTZ) coding, where each bit is represented by two pulses (signal states), resulting in:
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| :Gross bit rate = Symbol rate/2
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| A theoretical upper bound for the symbol rate in baud, symbols/s or pulses/s for a certain [[bandwidth (signal processing)|spectral bandwidth]] in hertz is given by the [[Nyquist rate|Nyquist law]]:
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| :Symbol rate ≤ Nyquist rate = 2 · bandwidth
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| In practice this upper bound can only be approached for [[line coding]] schemes and for so-called [[vestigal sideband]] digital modulation. Most other digital carrier-modulated schemes, for example [[amplitude-shift keying|ASK]], [[phase-shift keying|PSK]], [[quadrature amplitude modulation|QAM]] and [[OFDM]], can be characterized as [[double sideband]] modulation, resulting in the following relation:
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| :Symbol rate ≤ Bandwidth
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| In case of [[parallel port|parallel communication]], the gross bit rate is given by
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| :<math>\sum_{i = 1}^{n} \frac{\log_2 {M_i} }{T_i}</math>
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| where ''n'' is the number of parallel channels, ''M<sub>i</sub>'' is the number of symbols or levels of the [[modulation]] in the ''i''-th [[channel (communications)|channel]], and ''T<sub>i</sub>'' is the [[symbol duration time]], expressed in seconds, for the ''i''-th channel.
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| ===Information rate===
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| The [[physical layer]] '''net bitrate''',<ref name="Rappaport">Theodory S. Rappaport, [http://books.google.com/books?ei=rzTlTe20EIrKtAaDzN3wBQ&ct=result&hl=en&id=TbgQAQAAMAAJ&dq=%22net+bit+rate%22+wireless&q=%22net+bit+rate%22+ Wireless communications: principles and practice], Prentice Hall PTR, 2002</ref> '''information rate''',<ref name="Guimarães"/> '''useful bit rate''',<ref>Lajos Hanzo, Peter J. Cherriman, Jürgen Streit, [http://books.google.com/books?id=UPi04XAlfWQC&lpg=PA510&dq=%22useful%20bitrate%22&hl=en&pg=PA510#v=onepage&q=%22useful%20bitrate%22&f=false Video compression and communications: from basics to H.261, H.263, H.264, MPEG4 for DVB and HSDPA-style adaptive turbo-transceivers], Wiley-IEEE, 2007.</ref> '''payload rate''',<ref name="Bagad">V.S.Bagad, I.A.Dhotre, [http://books.google.com/books?id=srkNoDo3mbwC&lpg=SA6-PA26&dq=%22payload%20rate%20is%22&hl=en&pg=SA6-PA26#v=onepage&q=%22payload%20rate%20is%22&f=false Data Communication Systems], Technical Publications, 2009.</ref> '''net data transfer rate''',<ref name="3G"/> '''coded transmission rate''',<ref name="Pahlavan"/> '''effective data rate'''<ref name="Pahlavan"/> or [[wire speed]] (informal language) of a digital [[communication channel]] is the capacity excluding the [[physical layer]] protocol overhead, for example [[time division multiplex]] (TDM) [[framing bits]], redundant [[forward error correction]] (FEC) codes, equalizer training symbols and other [[channel coding]]. Error-correcting codes are common especially in wireless communication systems, broadband modem standards and modern copper-based high-speed LANs. The physical layer net bitrate is the datarate measured at a reference point in the interface between the datalink layer and physical layer, and may consequently include data link and higher layer overhead.
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| In modems and wireless systems, [[link adaptation]] (automatic adaption of the data rate and the modulation and/or error coding scheme to the signal quality) is often applied. In that context, the term '''peak bitrate''' denotes the net bitrate of the fastest and least robust transmission mode, used for example when the distance is very short between sender and transmitter.<ref>Sudhir Dixit, Ramjee Prasad [http://books.google.com/books?id=L2tA56H9rC0C&lpg=PA145&dq=%22peak%20bit%20rate%20is%22%20wireless&pg=PA145#v=onepage&q=peak%20bit%20rate%20is&f=false Wireless IP and building the mobile Internet], Artech House</ref> Some operating systems and network equipment may detect the "'''connection speed'''"<ref>Guy Hart-Davis,[http://books.google.com/books?id=oLU1XDaiZv8C&lpg=PA704&dq=detection%20%22%20connection%20speed%22%20windows&hl=sv&pg=PA704#v=onepage&q=connection%20speed&f=false Mastering Microsoft Windows Vista home: premium and basic], John Wiley and Sons, 2007</ref> (informal language) of a network access technology or communication device, implying the current net bit rate. Note that the term '''line rate''' in some textbooks is defined as gross bit rate,<ref name="Bagad"/> in others as net bit rate.
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| The relationship between the gross bit rate and net bit rate is affected by the FEC [[code rate]] according to the following.
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| :Net bit rate ≤ Gross bit rate · [[code rate]]
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| The connection speed of a technology that involves forward error correction typically refers to the physical layer ''net bit rate'' in accordance with the above definition.
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| For example, the net bitrate (and thus the "connection speed") of an [[IEEE 802.11a]] wireless network is the net bit rate of between 6 and 54 Mbit/s, while the gross bit rate is between 12 and 72 Mbit/s inclusive of error-correcting codes.
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| The net bit rate of ISDN2 [[Basic Rate Interface]] (2 B-channels + 1 D-channel) of 64+64+16 = 144 kbit/s also refers to the payload data rates, while the D channel signalling rate is 16 kbit/s.
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| The net bit rate of the Ethernet 100Base-TX physical layer standard is 100 Mbit/s, while the gross bitrate is 125 Mbit/second, due to the [[4B5B]] (four bit over five bit) encoding. In this case, the gross bit rate is equal to the symbol rate or pulse rate of 125 Mbaud, due to the [[NRZI]] [[line code]].
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| In communications technologies without forward error correction and other physical layer protocol overhead, there is no distinction between gross bit rate and physical layer net bit rate. For example, the net as well as gross bit rate of Ethernet 10Base-T is 10 Mbit/s. Due to the [[Manchester code|Manchester]] line code, each bit is represented by two pulses, resulting in a pulse rate of 20 Mbaud.
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| The "connection speed" of a [[V.92]] [[voiceband]] [[modem]] typically refers to the gross bit rate, since there is no additional error-correction code. It can be up to 56,000 bit/s [[downstream (computer science)|downstreams]] and 48,000 bit/s [[upstream (networking)|upstreams]]. A lower bit rate may be chosen during the connection establishment phase due to [[adaptive modulation]] - slower but more robust modulation schemes are chosen in case of poor [[signal-to-noise ratio]]. Due to data compression, the actual data transmission rate or throughput (see below) may be higher.
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| The [[channel capacity]], also known as the [[Shannon–Hartley theorem|Shannon]] capacity, is a theoretical upper bound for the maximum net bitrate, exclusive of forward error correction coding, that is possible without bit errors for a certain physical analog node-to-node [[communication link]].
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| :Net bit rate ≤ Channel capacity
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| The channel capacity is proportional to the [[analog bandwidth]] in hertz. This proportionality is called [[Hartley's law]]. Consequently the net bit rate is sometimes called [[digital bandwidth]] capacity in bit/s.
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| ===Network throughput===
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| {{main|Throughput}}
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| The term ''[[throughput]]'', essentially the same thing as '''[[bandwidth (computing)|digital bandwidth]] consumption''', denotes the achieved average useful bit rate in a computer network over a logical or physical communication link or through a network node, typically measured at a reference point above the [[datalink layer]]. This implies that the throughput often excludes data link layer protocol overhead. The throughput is affected by the traffic load from the data source in question, as well as from other sources sharing the same network resources. See also [[Measuring network throughput]].
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| ===Goodput (data transfer rate)===
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| {{main|Goodput}}
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| ''[[Goodput]]'' or '''data transfer rate''' refers to the achieved average net bit rate that is delivered to the [[application layer]], exclusive of all protocol overhead, data packets retransmissions, etc. For example, in the case of file transfer, the goodput corresponds to the achieved '''file transfer rate'''. The file transfer rate in bit/s can be calculated as the file size (in bytes) divided by the file transfer time (in seconds) and multiplied by eight.
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| As an example, the goodput or data transfer rate of a V.92 voiceband modem is affected by the modem physical layer and data link layer protocols. It is sometimes higher than the physical layer data rate due to [[V.44]] [[data compression]], and sometimes lower due to bit-errors and [[automatic repeat request]] retransmissions.
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| If no data compression is provided by the network equipment or protocols, we have the following relation:
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| :Goodput ≤ Throughput ≤ Maximum throughput ≤ Net bit rate
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| for a certain communication path.
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| ===Multimedia encoding {{anchor | Multimedia encoding bit rate}}===
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| In digital [[multimedia]], ''bit rate'' often refers to the number of bits used per unit of playback time to represent a continuous medium such as [[sound recording|audio]] or [[video]] after [[source coding]] (data compression). The encoding bit rate of a multimedia file is the size of a multimedia file in [[bytes]] divided by the playback time of the recording (in seconds), multiplied by eight.
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| For realtime [[streaming multimedia]], the encoding bit rate is the [[goodput]] that is required to avoid interrupt:
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| :Encoding bit rate = Required goodput
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| The term [[average bitrate]] is used in case of [[variable bitrate]] multimedia source coding schemes. In this context, the '''peak bit rate''' is the maximum number of bits required for any short-term block of compressed data.<ref>Khalid Sayood, [http://books.google.com/books?id=LjQiGwyabVwC&pg=PA264&dq=%22peak+bit+rate%22&hl=en&ei=6zflTfGLNcXQsganv7n3BQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CDcQ6AEwAg#v=onepage&q=%22peak%20bit%20rate%22&f=false Lossless compression handbook], Academic Press, 2003.</ref>
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| A theoretical lower bound for the encoding bit rate for [[lossless data compression]] is the [[source information rate]], also known as the ''entropy rate''. | |
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| :Entropy rate ≤ Multimedia bit rate
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| ==Prefixes==
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| When quantifying large bit rates, [[SI prefix]]es (also known as [[Metric prefix]]es or Decimal prefixes) are used, thus:
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| {|
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| |-
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| |align="right"| 1,000 bit/s ||rate = 1 [[kbit/s]] (one [[kilobit]] or one [[thousand]] bits per second)
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| |-
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| |align="right"| 1,000,000 bit/s ||rate = 1 [[Mbit/s]] (one [[megabit]] or one [[million]] bits per second)
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| |-
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| |align="right"| 1,000,000,000 bit/s ||rate = 1 [[Gbit/s]] (one [[gigabit]] or one [[1000000000 (number)|billion]] bits per second)
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| |}
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| [[Binary prefix]]es 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 [[kibibyte|KiB]]/s = 1024 byte/s = 8192 bit/s, and 1 [[mebibyte|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.
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| ==Progress trends==
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| These are examples of physical layer net bit rates in proposed communication standard interfaces and devices:
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| {| class="wikitable" style="margin: 1em auto 1em auto"
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| |-
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| ! WAN [[modem]]s
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| ! [[Ethernet]] LAN
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| ! [[WiFi]] [[WLAN]]
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| ! [[Comparison of mobile phone standards|Mobile data]]
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| |-
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| * 1972: [[Acoustic coupler]] 300 baud
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| * 1977: 1200 baud [[Modem#The Carterfone decision|Vadic and Bell 212A]]
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| * 1986: [[ISDN]] introduced with two 64 kbit/s channels (144 kbit/s gross bit rate)
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| * 1990: [[V.32bis]] [[modem]]s: 2400 / 4800 / 9600 / 19200 bit/s
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| * 1994: [[V.34 (recommendation)|V.34]] modems with 28.8 kbit/s
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| * 1995: [[V.90 (recommendation)|V.90]] modems with 56 kbit/s downstreams, 33.6 kbit/s upstreams
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| * 1999: [[V.92]] modems with 56 kbit/s downstreams, 48 kbit/s upstreams
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| * 1998: [[Asymmetric Digital Subscriber Line|ADSL]] up to 8 Mbit/s,
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| * 2003: [[ADSL2]] up to 12 Mbit/s
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| * 2005: [[ADSL2+]] up to 24 Mbit/s
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| * 2005: [[VDSL2]] up to 200 Mbit/s
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| * 1975: Experimental 2.94 Mbit/s
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| * 1981: 10 Mbit/s [[10BASE5]] ([[coax]])
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| * 1990: 10 Mbit/s [[10BASE-T]] ([[twisted pair]])
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| * 1995: 100 Mbit/s [[Fast Ethernet]]
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| * 1999: [[Gigabit Ethernet]]
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| * 2003: [[10 Gigabit Ethernet]]
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| * 2010: [[100 Gigabit Ethernet]]
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| * 1997: [[IEEE 802.11|802.11]] 2 Mbit/s
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| * 1999: [[IEEE 802.11|802.11b]] 11 Mbit/s
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| * 1999: [[IEEE 802.11|802.11a]] 54 Mbit/s
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| * 2003: [[IEEE 802.11|802.11g]] 54 Mbit/s
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| * 2007: [[IEEE 802.11|802.11n]] 600 Mbit/s
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| * 2012: [[IEEE 802.11|802.11ac]] ~1000 Mbit/s
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| * [[1G]]:
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| ** 1981: [[Nordic Mobile Telephone|NMT]] 1200 bit/s
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| * [[2G]]:
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| ** 1991: [[GSM]] [[circuit switched data|CSD]] and [[D-AMPS]] 14.4 kbit/s
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| ** 2003: [[Enhanced Data Rates for GSM Evolution|GSM EDGE]] 296 kbit/s down, 118.4 kbit/s up
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| * [[3G]]:
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| ** 2001: [[UMTS]]-FDD ([[WCDMA]]) 384 kbit/s
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| ** 2007: UMTS [[HSDPA]] 14.4 Mbit/s
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| ** 2008: UMTS [[High Speed Packet Access|HSPA]] 14.4 Mbit/s down, 5.76 Mbit/s up
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| ** 2009: [[HSPA+]] (Without MIMO) 28 Mbit/s downstreams (56 Mbit/s with 2x2 MIMO), 22 Mbit/s upstreams
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| ** 2010: CDMA2000 [[EV-DO]] Rev. B 14.7 Mbit/s downstreams
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| ** 2011: [[HSPA+]] accelerated (With MIMO) 42 Mbit/s downstreams
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| * [[Pre-4G]]:
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| ** 2007: [[Mobile WiMAX]] (IEEE 802.16e) 144 Mbit/s down, 35 Mbit/s up.
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| ** 2009: [[3GPP Long Term Evolution|LTE]] 100 Mbit/s downstreams (360 Mbit/s with MIMO 2x2), 50 Mbit/s upstreams
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| See also [[Comparison of mobile phone standards]]
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| |}
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| For more examples, see [[List of device bit rates]], [[Spectral efficiency comparison table]] and [[OFDM system comparison table]].
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| ==Multimedia {{anchor | Bitrates in multimedia}}==
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| In digital multimedia, bitrate represents the amount of information, or detail, that is stored per unit of time of a recording. The bitrate depends on several factors:
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| *The original material may be sampled at different frequencies
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| *The samples may use different numbers of bits
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| *The data may be encoded by different schemes
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| *The information may be digitally [[data compression|compressed]] by different algorithms or to different degrees
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| Generally, choices are made about the above factors in order to achieve the desired trade-off between minimizing the bitrate and maximizing the quality of the material when it is played.
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| If [[lossy data compression]] is used on audio or visual data, differences from the original signal will be introduced; if the compression is substantial, or lossy data is decompressed and recompressed, this may become noticeable in the form of [[compression artifact]]s. Whether these affect the perceived quality, and if so how much, depends on the compression scheme, encoder power, the characteristics of the input data, the listener’s perceptions, the listener's familiarity with artifacts, and the listening or viewing environment.
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| The bitrates in this section are approximately the ''minimum'' that the ''average'' listener in a typical listening or viewing environment, when using the best available compression, would perceive as not significantly worse than the reference standard:
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| <!-- PLEASE understand the above sentence before making changes. References to controlled tests would be valuable. But this discussion really belongs elsewhere. -->
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| ===Audio ===
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| CD-DA, the standard audio CD, is said to have a data rate of 44.1 kHz/16, meaning that the audio data was sampled 44,100 times per second and with a bit depth of 16. CD-DA is also [[Stereophonic sound|stereo]], using a left and right [[Audio channel|channel]], so the amount of audio data per second is double that of mono, where only a single channel is used.
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| The bit rate of PCM audio data can be calculated with the following formula:
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| :<math>bit\ rate = sample\ rate \times bit\ depth \times channels</math>
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| For example, the bit rate of a CD-DA recording (44.1 kHz sampling rate, 16 bits per sample and 2 channels) can be calculated as follows:
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| :<math>44,100 \times 16 \times 2 = 1,411,200\ \mathrm{bit/s} = 1,411.2\ \mathrm{kbit/s}</math>
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| The cumulative size of a length of audio data (excluding a file [[Header (computing)|header]] or other [[metadata]]) can be calculated using the following formula:
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| :<math>size\ in\ bits = sample\ rate \times bit\ depth \times channels \times length\ of\ time</math>
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| The cumulative size in bytes can be found by dividing the file size in bits by the number of bits in a byte, which is 8:
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| :<math>size\ in\ bytes = \frac{size\ in\ bits}{8}</math>
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| Therefore, 80 minutes (4,800 seconds) of CD-DA data requires 846,720,000 bytes of storage:
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| :<math>\frac{44,100 \times 16 \times 2 \times 4,800}{8} = 846,720,000\ \mathrm{bytes} \approx 847\ \mathrm{MB}</math>
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| ==== MP3 ====
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| The [[MP3]] audio format [[lossy data compression]]. Audio quality improves with increasing bitrate.
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| * 32 kbit/s - generally acceptable only for speech
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| * 96 kbit/s - generally used for speech or low-quality streaming
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| * 128 or 160 kbit/s – mid-range bitrate quality
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| * 192 kbit/s - a commonly used high-quality bitrate
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| * 320 kbit/s - highest level supported by [[MP3]] standard
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| ====Other audio====
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| * 800 bit/s – minimum necessary for recognizable speech, using the special-purpose [[FS-1015]] [[speech encoding|speech codecs]].
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| * 1400 bit/s – lowest bitrate open-source speech codec [[Codec2]].<ref>{{cite web|url=http://www.rowetel.com/blog/?p=2255|title=Codec2 at 1400 bits/s|publisher=David Rowe|date=|accessdate=2011-11-22}}</ref>
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| * 2.15 kbit/s – minimum bitrate available through the open-source [[Speex]] codec.
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| * 8 kbit/s – [[telephone]] quality using speech codecs.
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| * 32-500 kbit/s – [[Lossy compression|lossy audio]] as used in [[Ogg Vorbis]].
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| * 256 kbit/s – Digital Audio Broadcasting ([[Digital Audio Broadcasting|DAB]].) [[MPEG-1 Audio Layer II|MP2]] bit rate required to achieve a high quality signal.<ref>Page 26 of BBC R&D White Paper WHP 061 June 2003, DAB: An introduction to the DAB Eureka system and how it works http://downloads.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP061.pdf</ref>
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| * 400 kbit/s–1,411 kbit/s – [[Lossless compression|lossless audio]] as used in formats such as [[Free Lossless Audio Codec]], [[WavPack]], or [[Monkey's Audio]] to compress CD audio.
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| * 1,411.2 kbit/s – [[Linear PCM]] sound format of [[CD-DA]].
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| * 5,644.8 kbit/s - [[Direct Stream Digital|DSD]], which is a trademarked implementation of [[Pulse-density modulation|PDM]] sound format used on [[Super Audio CD]].<ref>Extremetech.com, Leslie Shapiro, 2 July 2001. ''Surround Sound:'' [http://www.extremetech.com/article2/0,2845,1180143,00.asp ''The High-End: SACD and DVD-Audio''.] Retrieved 19 May 2010. 2 channels, 1-bit, 2822.4 kHz DSD audio (2x1x2,822,400)= 5,644,800 bits/s</ref>
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| * 6.144 Mbit/s - E-AC-3 (Dolby Digital Plus), which is an enhanced coding system based on the AC-3 codec.
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| * 18 Mbit/s - advanced lossless audio codec based on [[Meridian Lossless Packing]].
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| ===Video===
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| * 16 kbit/s – [[videophone]] quality (minimum necessary for a consumer-acceptable "talking head" picture using various video compression schemes)
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| * 128–384 kbit/s – business-oriented [[videoconferencing]] quality using video compression
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| * 1.15 Mbit/s max – [[VCD]] quality (using [[MPEG-1|MPEG1]] compression)<ref>{{cite web|url=http://www.icdia.co.uk/cdprosupport/encoding/pink/mpeg1_specs.htm | title = MPEG1 Specifications |publisher=ICDia | location = UK |date= |accessdate=2011-07-11}}</ref>
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| * 3.5 Mbit/s typ — [[Standard-definition television]] quality (with bit-rate reduction from MPEG-2 compression)
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| * 9.8 Mbit/s max – [[DVD]] (using [[MPEG2]] compression)<ref>{{cite web|url=http://dvd.sourceforge.net/dvdinfo/dvdmpeg.html |title= DVD-MPEG differences | publisher = Sourceforge |date= |accessdate=2011-07-11}}</ref>
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| * 8 to 15 Mbit/s typ – [[High-definition television|HDTV]] quality (with bit-rate reduction from MPEG-4 AVC compression)
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| * 19 Mbit/s approximate — [[HDV]] 720p (using [[MPEG2]] compression)<ref name="hdv-info.org">{{Citation | url = http://www.hdv-info.org/HDVSpecifications.pdf | title = HDV Specifications | publisher = HDV Information | format = [[PDF]]}}.</ref>
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| * 24 Mbit/s max — [[AVCHD]] (using [[H.264/MPEG-4 AVC|MPEG4 AVC]] compression)<ref>{{cite web|url=http://www.avchd-info.org/format/ |title=Avchd Information | publisher = AVCHD Info |date= |accessdate=2011-07-11}}</ref>
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| * 25 Mbit/s approximate — [[HDV]] 1080i (using [[MPEG2]] compression)<ref name="hdv-info.org"/>
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| * 29.4 Mbit/s max – [[HD DVD]]
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| * 40 Mbit/s max – [[Blu-ray Disc]] (using [[MPEG2]], [[H.264/MPEG-4 AVC|AVC]] or [[VC-1]] compression)<ref>{{Citation | format = [[PDF]] | type = white paper | title = Blu-ray Disc Format 2.B Audio Visual Application Format Specifications for BD-ROM Version 2.4 | date = May 2010 | page = 17 | chapter = 3.3 Video Streams | url = http://www.blu-raydisc.com/assets/Downloadablefile/BD-ROM-AV-WhitePaper_100604%281%29-15916.pdf}}.</ref>
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| ===Notes===
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| For technical reasons (hardware/software protocols, overheads, encoding schemes, etc.) the ''actual'' bit rates used by some of the compared-to devices may be significantly higher than what is listed above. For example:
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| * Telephone circuits using [[Mu-law algorithm|µlaw]] or [[A-law algorithm|A-law]] [[companding]] (pulse code modulation) – 64 kbit/s
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| * CDs using [[CD-DA]] [[Pulse code modulation|PCM]] – 1.4 Mbit/s
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| ==See also==
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| {{Div col||25em}}
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| * [[Dolby AC-3]]
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| * [[Audio bit depth]]
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| * [[Average bitrate]]
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| * [[Bandwidth (computing)]]
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| * [[Baud]] (symbol rate)
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| * [[Bit-synchronous operation]]
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| * [[Clock rate]]
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| * [[Code rate]]
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| * [[Constant bitrate]]
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| * [[Data rate units]]
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| * [[Data signaling rate]]
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| * [[List of device bit rates]]
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| * [[Measuring network throughput]]
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| * [[Orders of magnitude (bit rate)]]
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| * [[Spectral efficiency]]
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| * [[Variable bitrate]]
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| {{Div col end}}
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| ==References==
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| {{Reflist|30em}}
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| {{FS1037C MS188}}
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| ==External links==
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| * [http://dvd-hq.info/bitrate_calculator.php DVD-HQ bit rate calculator] Calculate bit rate for various types of digital video media.
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| * [http://www.maximumpc.com/article/do_higher_mp3_bit_rates_pay_off?page=0%2C0 Maximum PC - Do Higher MP3 Bit Rates Pay Off?]
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| {{Compression Methods}}
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| {{DEFAULTSORT:Bit Rate}}
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| [[Category:Data transmission]]
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| [[Category:Units of measurement|Bits per second]]
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