"use. Unit prefix A unit prefix is a specifier or mnemonic that is prepended to units of measurement to indicate multiples or fractions of the units. Units of various sizes are commonly formed by the use of such prefixes. The prefixes of the metric system, such as ""kilo"" and ""milli"", represent multiplication by powers of ten. In information technology it is common to use binary prefixes, which are based on powers of two. Historically, many prefixes have been used or proposed by various sources, but only a narrow set has been recognised by standards organisations. The prefixes of the metric"
"Metric prefix A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or fraction of the unit. While all metric prefixes in common use today are decadic, historically there have been a number of binary metric prefixes as well. Each prefix has a unique symbol that is prepended to the unit symbol. The prefix ""kilo-"", for example, may be added to ""gram"" to indicate ""multiplication"" by one thousand: one kilogram is equal to one thousand grams. The prefix ""milli-"", likewise, may be added to ""metre"" to indicate ""division"" by one thousand; one"
"millimetre is equal to one thousandth of a metre. Decimal multiplicative prefixes have been a feature of all forms of the metric system, with six dating back to the system's introduction in the 1790s. Metric prefixes have even been prepended to non-metric units. The SI prefixes are standardized for use in the International System of Units (SI) by the International Bureau of Weights and Measures (BIPM) in resolutions dating from 1960 to 1991. Since 2009, they have formed part of the International System of Quantities. The BIPM specifies twenty prefixes for the International System of Units (SI). Each prefix name"
"precede a basic unit of measure to indicate a decadic multiple and fraction of a unit. Each prefix has a unique symbol that is prepended to the unit symbol. Some of the prefixes date back to the introduction of the metric system in the 1790s, but new prefixes have been added, and some have been revised. The International Bureau of Weights and Measures has standardised twenty metric prefixes in resolutions dating from 1960 to 1991 for use with the International System of Units (SI). Although formerly in use, the SI disallows combining prefixes; the microkilogram or centimillimetre, for example, are"
"decibel. Metric prefixes rarely appear with imperial or US units except in some special cases (e.g., microinch, kilofoot, kilopound or 'kip'). They are also used with other specialized units used in particular fields (e.g., megaelectronvolt, gigaparsec, millibarn). They are also occasionally used with currency units (e.g., gigadollar), mainly by people who are familiar with the prefixes from scientific usage. In geology and paleontology, the year, with symbol a (from the Latin ""annus""), is commonly used with metric prefixes: ka, Ma, and Ga. When an SI prefix is affixed to a root word, the prefix carries the stress, while the root"
"1024. To address this conflict, a new set of binary prefixes has been introduced, which is based on powers of 2. Therefore, 1024 bytes are defined as one kibibyte (1 KiB). When units occur in exponentiation, such as in square and cubic forms, any multiplier prefix is considered part of the unit, and thus included in the exponentiation. Kilo- Kilo is a decimal unit prefix in the metric system denoting multiplication by one thousand (10). It is used in the International System of Units where it has the unit symbol k, in lower case. The prefix ""kilo"" is derived from"
"used to multiply the unit by 1000, and the prefix ""milli"" is to indicate a one-thousandth part of the unit. Thus the ""kilogram"" and ""kilometre"" are a thousand grams and metres respectively, and a ""milligram"" and ""millimetre"" are one thousandth of a gram and metre respectively. These relations can be written symbolically as: In the early days, multipliers that were positive powers of ten were given Greek-derived prefixes such as ""kilo-"" and ""mega-"", and those that were negative powers of ten were given Latin-derived prefixes such as ""centi-"" and ""milli-"". However, 1935 extensions to the prefix system did not follow"
"Mega- Mega is a unit prefix in metric systems of units denoting a factor of one million (10 or ). It has the unit symbol M. It was confirmed for use in the International System of Units (SI) in 1960. ""Mega"" comes from . When units occur in exponentiation, such as in square and cubic forms, any multiples-prefix is considered part of the unit, and thus included in the exponentiation. In some fields of computing, ""mega"" may sometimes denote 1,048,576 (2) of information units, for example, a megabyte, a megaword, but denotes (10) units of other quantities, for example, transfer"
"not permitted. Prefixes corresponding to powers of one thousand are usually preferred, however, units such as the hectopascal, hectare, decibel, centimetre, and centilitre, are commonly used. In mathematical contexts, the unit prefixes are always considered part of the unit, so that, e.g., in exponentiation, 1 km means one square kilometre not one thousand square metre and 1 cm means one cubic centimetre not one hundredth of a cubic metre. In general, prefixes are used with any metric unit, but may also be used with non-metric units. Some combinations, however, are more common than others. The choice of prefixes for a"
"""symbol"" for any SI unit kilometres per hour are always written ""km/h"" regardless of local script. Both the symbols used for the prefix of a metric unit and the unit itself are case-sensitive. Prefixes representing multipliers up to and including ""1000"" (k) are written in lower-case letters and those above 1000 are written in upper-case letters. This is particularly important for some units of measure for example a hearing aid requires about 1 mW (milliwatt) while the central air conditioning unit in a large office block might require 1 MW (megawatt). The symbol for the unit name itself is written"
"rates: = . The prefix ""mebi-"" has been suggested as a prefix for 2 to avoid ambiguity. Mega- Mega is a unit prefix in metric systems of units denoting a factor of one million (10 or ). It has the unit symbol M. It was confirmed for use in the International System of Units (SI) in 1960. ""Mega"" comes from . When units occur in exponentiation, such as in square and cubic forms, any multiples-prefix is considered part of the unit, and thus included in the exponentiation. In some fields of computing, ""mega"" may sometimes denote 1,048,576 (2) of information"
"are one thousand millimetres to the metre and one thousand metres to the kilometre. The prefixes are never combined, so for example a millionth of a metre is a ""micrometre"", not a millimillimetre. Multiples of the kilogram are named as if the gram were the base unit, so a millionth of a kilogram is a ""milligram"", not a microkilogram. When prefixes are used to form multiples and submultiples of SI base and derived units, the resulting units are no longer coherent. The BIPM specifies twenty prefixes for the International System of Units (SI): Many non-SI units continue to be used"
"measurement are spelled out, for example, codice_1 formats as ""3 THz"". Some of the prefixes formerly used in the metric system have fallen into disuse and were not adopted into the SI. The decimal prefix ""myria-"" (sometimes also written as ""myrio-"") (ten thousand) as well as the binary prefixes ""double-"" and ""demi-"", denoting a factor of 2 and (one half), respectively, were parts of the original metric system adopted by France in 1795. These were not retained when the SI prefixes were internationally adopted by the 11th CGPM conference in 1960. Other metric prefixes used historically include hebdo- (10) and"
"1,000,000 1,000,000 (one million), or one thousand thousand, is the natural number following 999,999 and preceding 1,000,001. The word is derived from the early Italian ""millione"" (""milione"" in modern Italian), from ""mille"", ""thousand"", plus the augmentative suffix ""-one"". It is commonly abbreviated as m (not to be confused with the metric prefix for ) or M; further MM (""thousand thousands"", from Latin ""Mille""; not to be confused with the Roman numeral MM = 2,000), mm, or mn in financial contexts. In scientific notation, it is written as or 10. Physical quantities can also be expressed using the SI prefix mega"
"the introduction of metric prefixes to derive bigger and smaller sizes from base unit names. Examples include ""kilo"" for 1000, ""hecto"" for 100, ""centi"" for 1/100 and ""milli"" for 1/1000. The list of metric prefixes has expanded in modern times to encompass a wider range of measurements. While the common units of time, minute, hour, day, month and year, are not decimalised, there have been proposals for decimalisation of the time of day and decimal calendar systems. Astronomers use a decimalised Julian day number to record and predict events. Decimal currencies have sub-units based on a factor of 10. There"
"Micro- Micro- (Greek letter μ or legacy micro symbol µ) is a unit prefix in the metric system denoting a factor of 10 (one millionth). Confirmed in 1960, the prefix comes from the Greek (""""), meaning ""small"". The symbol for the prefix comes from the Greek letter μ (mu). It is the only SI prefix which uses a character not from the Latin alphabet. ""mc"" is commonly used as a prefix when the character ""μ"" is not available; for example, ""mcg"" commonly denotes a microgram. Also the letter u instead of μ is allowed by one of the ISO documents."
"and milligauss). Metric prefixes may also be used with non-metric units. The choice of prefixes with a given unit is usually dictated by convenience of use. Unit prefixes for amounts that are much larger or smaller than those actually encountered are seldom used. In use, the kilogram, gram, milligram, microgram, and smaller are fairly common. However, megagram (and gigagram, teragram, etc.) are rarely used; tonnes (and kilotonnes, megatonnes, etc. – although these units generally are not used as a measure of mass ""per se"", but rather TNT energy equivalent of a mass) or scientific notation are used instead. Megagram is"
"meaning 1000 and respectively, were commonly used in the electronics industry before World War II. Along with ""giga-"" or G-, meaning , they are now known as SI prefixes after the International System of Units (SI), introduced in 1960 to formalize aspects of the metric system. The International System of Units does not define units for digital information but notes that the SI prefixes may be applied outside the contexts where base units or derived units would be used. But as computer main memory in a binary-addressed system is manufactured in sizes that were easily expressed as multiples of 1024,"
"scale of nanometres"". See nanoscopic scale. Nano- Nano- (symbol n) is a unit prefix meaning ""one billionth"". Used primarily with the metric system, this prefix denotes a factor of 10 or . It is frequently encountered in science and electronics for prefixing units of time and length. Examples: The prefix derives from the Greek (Latin ""nanus""), meaning ""dwarf"". The General Conference on Weights and Measures (CGPM) officially endorsed the usage of ""nano"" as a standard prefix in 1960. When used as a prefix for something other than a unit of measure (as for example in words like ""nanoscience""), nano refers"
"The prefixes hecto, deca, deci, and centi are commonly used for everyday purposes, and the centimetre (cm) is especially common. However, some modern building codes require that the millimetre be used in preference to the centimetre, because ""use of centimetres leads to extensive usage of decimal points and confusion"". Prefixes may not be used in combination. This also applies to mass, for which the SI base unit (kilogram) already contains a prefix. For example, milligram (mg) is used instead of microkilogram (μkg). In the arithmetic of measurements having units, the units are treated as multiplicative factors to values. If they"
"to mean eight bits (1 B = 8 bit). Therefore, 1 kB = 8000 bit. One thousand kilobytes (1000 kB) is equal to one megabyte (1 MB), where 1 MB is one million bytes. The kilobyte has traditionally been used to refer to 1024 bytes (2 B), a usage still common. The usage of the metric prefix ""kilo"" for binary multiples arose as a convenience, because 1000 approximates 1024. The binary interpretation of metric prefixes is still prominently used by the Microsoft Windows operating system, which is used on 90% of the world's personal computers. They are also used for"
"Nano- Nano- (symbol n) is a unit prefix meaning ""one billionth"". Used primarily with the metric system, this prefix denotes a factor of 10 or . It is frequently encountered in science and electronics for prefixing units of time and length. Examples: The prefix derives from the Greek (Latin ""nanus""), meaning ""dwarf"". The General Conference on Weights and Measures (CGPM) officially endorsed the usage of ""nano"" as a standard prefix in 1960. When used as a prefix for something other than a unit of measure (as for example in words like ""nanoscience""), nano refers to nanotechnology, or means ""on a"
"Zetta- Zetta is a decimal unit prefix in the metric system denoting a factor of 10 or . The prefix was added as an SI prefix to the International System of Units (SI) in 1991 and has the symbol Z. Zetta is evocative of the Latin numeral , meaning ""seven"". Therefore it was used to denote the seventh power of 1000. A prefix of the same value, ""hepta"", was informally introduced a few years before the promulgation of zetta. It was formed from the Greek (), also meaning ""seven"". ""Hepta"" never received official sanction and is obsolete. Zeta (), although"
"metre is ""mǐ""; this can take the Chinese standard SI prefixes (for ""kilo-"", ""centi-"", etc.). A kilometre, however, may also be called ""gōnglǐ"", i.e. a metric ""lǐ"". In the engineering field, traditional units are rounded up to metric units.For example, the Chinese word sī is used to express 0.01 mm. These correspond to the measures listed simply as ""China"" in ""The Measures, Weights, & Moneys of All Nations"" Metric and other standard length units can be squared by the addition of the prefix ""píngfāng"". For example, a square kilometre is ""píngfāng gōnglǐ"". These units are used to measure cereal grains,"
"Binary prefix A binary prefix is a unit prefix for multiples of units in data processing, data transmission, and digital information, notably the bit and the byte, to indicate multiplication by a power of 2. The computer industry has historically used the units ""kilobyte"", ""megabyte"", and ""gigabyte"", and the corresponding symbols KB, MB, and GB, in at least two slightly different measurement systems. In citations of main memory (RAM) capacity, ""gigabyte"" customarily means bytes. As this is a power of 1024, and 1024 is a power of two (2), this usage is referred to as a binary measurement. In most"
"Myria- Myria- (symbol my) is a now obsolete decimal metric prefix denoting a factor of 10 (ten thousand). It originates from the Greek μύριοι (""mýrioi"") (myriad). The prefix was part of the original metric system adopted by France in 1795, but was not adopted when the SI prefixes were internationally adopted by the 11th CGPM conference in 1960. In 1685 John Wallis proposed the usage of myrio. Also, in 19th century English it was sometimes spelled myrio, in line with a puristic opinion by Thomas Young. The ""myriametre"" (10 km) is occasionally encountered in 19th-century train tariffs, or in some"
"The units MBtu and MMBtu are used in the natural gas and other industries to indicate 1,000 and 1,000,000 BTUs, respectively. There is an ambiguity in that the metric system uses the prefix ""M"" to indicate one million (1,000,000), and ""MBtu"" is also used to indicate one million BTUs. Because of this ambiguity, some authors have deprecated the use of MBtu. Energy analysts accustomed to the metric ""k"" for 1,000 are more likely to use MBtu to represent one million, especially in documents where M represents one million in other energy or cost units, such as MW, MWh and $."
"acceptable. Myria- Myria- (symbol my) is a now obsolete decimal metric prefix denoting a factor of 10 (ten thousand). It originates from the Greek μύριοι (""mýrioi"") (myriad). The prefix was part of the original metric system adopted by France in 1795, but was not adopted when the SI prefixes were internationally adopted by the 11th CGPM conference in 1960. In 1685 John Wallis proposed the usage of myrio. Also, in 19th century English it was sometimes spelled myrio, in line with a puristic opinion by Thomas Young. The ""myriametre"" (10 km) is occasionally encountered in 19th-century train tariffs, or in"
"has a symbol that is used in combination with the symbols for units of measure. For example, the symbol for ""kilo-"" is 'k', and is used to produce 'km', 'kg', and 'kW', which are the SI symbols for kilometre, kilogram, and kilowatt, respectively. Where the Greek letter 'μ' is unavailable, the symbol for micro 'µ' may be used. Where both variants are unavailable, the micro prefix is commonly written as the lowercase Latin letter 'u'. Prefixes corresponding to an integer power of one thousand are generally preferred. Hence ""100 m"" is preferred over ""1 hm"" (hectometre) or ""10 dam"" (decametres)."
"For each physical quantity, a number of different units (some only of historical interest) are shown and expressed in terms of the corresponding SI unit. Conversions between units in the metric system are defined by their prefixes (for example, 1 kilogram = 1000 grams, 1 milligram = 0.001 grams) and are thus not listed in this article. Exceptions are made if the unit is commonly known by another name (for example, 1 micron = 10 metre). Within each table, the units are listed alphabetically, and the SI units (base or derived) are highlighted. !Name of unit !Symbol !Definition !Relation to"
"true. The decimal SI prefixes ""kilo"", ""mega"", ""giga"", ""tera"", etc., are powers of 10 = 1000. The binary prefixes ""kibi"", ""mebi"", ""gibi"", ""tebi"", etc. respectively refer to the corresponding power of 2 = 1024. In casual usage, when 1024 is a close enough approximation of 1000, the two corresponding prefixes are equivalent. Note: this page mixes between two kinds of entropies: These two definitions are not entirely equivalent, see Entropy in thermodynamics and information theory. For comparison, the Avogadro constant is entities per mole, based upon the number of atoms in 12 grams of carbon-12 isotope. In 2012, some hard"
"given unit has often arisen by convenience of use and historical developments. Unit prefixes that are much larger or smaller than encountered in practice are seldom used, albeit valid combinations. In most contexts only a few, the most common, combinations are established. For example, prefixes for multiples greater than one thousand are rarely applied to the gram or metre. Some prefixes used in older versions of the metric system are no longer used. The prefixes ""myria-"", (from the Greek μύριοι, ""mýrioi""), ""double-"" and ""demi-"", denoting a factors of , 2 and respectively, were parts of the original metric system adopted"
"architectures. However, most standards bodies have deprecated this usage in favor of a set of binary prefixes, in which this quantity is designated by the unit mebibyte (MiB). Less common is a convention that used the megabyte to mean 1000×1024 () bytes. The megabyte is commonly used to measure either 1000 bytes or 1024 bytes. The interpretation of using base 1024 originated as a compromise technical jargon for the byte multiples that needed to be expressed by the powers of 2 but lacked a convenient name. As 1024 (2) approximates 1000 (10), roughly corresponding to the SI prefix kilo-, it"