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Appendix:SI units
Definition from Dictionary, a free dictionary
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SI units
SI is an abbreviation of Système International (d'Unités) [International System (of Units)] and is a standard metric system of units adopted for official scientific use. For more information, see Wikipedia's article on SI.
Note: this page is simply a collection of links to the names of SI units and their prefixes and multiples. For further information, see the Wikipedia articles SI base units and SI derived units.
Base units (with symbols in parentheses)

Derived units (with symbols in parentheses)
Alternative names for SI units and their multiples and submultiples

Former names for SI units
SI prefixes
prefix  sym  multiplier  notes 

yotta  Y  10^{24}  
zetta  Z  10^{21}  
exa  X  10^{18}  
peta  P  10^{15}  
tera  T  10^{12}  
giga  G  10^{9}  
mega, meg  M  10^{6}  1 
kilo  k  10^{3}  
hecto  h  10^{2}  2 
deca, deka  da  10^{1}  2 
deci  d  10^{–1}  
centi  c  10^{–2}  
milli  m  10^{–3}  
micro  µ, u  10^{–6}  
nano  n  10^{–9}  
pico  p  10^{–12}  
femto  f  10^{–15}  
atto  a  10^{–18}  
zepto  z  10^{–21}  
yocto  y  10^{–24} 
Notes:
Binary prefixes
The following prefixes are not part of SI. They were adopted by the IEC to express binary multiples.
prefix  sym  multiplier 

exbi  Ei  2^{60} 
pebi  Pi  2^{50} 
tebi  Ti  2^{40} 
gibi  Gi  2^{30} 
mebi  Mi  2^{20} 
kibi  Ki  2^{10} 
Former prefixes
These prefixes were never part of SI.
prefix  multiplier  equivalent 

hectokilo  10^{5}  
myria  10^{4}  
millimilli  10^{–6}  micro 
millimicro  10^{–9}  nano 
micromicro  10^{–12}  pico 
Commonly used multiples of units
 The table below shows which prefixes are most commonly used with each unit. In theory, any combination of a prefix and a unit is possible. In practice, only those multiples that are of practical use are used. Multiples towards the left and right of the table tend to gain currency as advances in technology and miniaturisation make them meaningful.
 Links are to combinations that are in relatively common scientific use. Blank entries indicate combinations that are rare or not used.
 Notes:
 Units are ordered alphabetically by their symbol. Prefixes are ordered from largest to smallest.
 It is the gram (g) that takes prefixes, not the kilogram.
 Some combinations have special names; for example, 10^{6} grams is called a tonne, not a "megagram".
 The multiples in the grey columns are not in official scientific usage.
 The table lists multiples of SI units only. Other units that use the SI prefixes, such as kilobyte and millibar, are not given here.
 The table is currently incomplete. More links will be added later.
(Sources: ; Oxford English Dictionary, 2nd ed.)
Y  Z  E  P  T  G  M  k  h  da  Unit  d  c  m  μ  n  p  f  a  z  y 

MA  kA  A  mA  μA  nA  
PBq  TBq  GBq  Bq  
C  
°C  
cd  
F  mF  μF  nF  pF  
t, Mg  kg  hg  dag  g  dg  cg  mg  μg  
Gy  
H  mH  μH  nH  
PHz  THz  GHz  MHz  kHz  Hz  
kJ  J  
K  
kat  
lm  
klx  lx  
km  hm  dam  m  dm  cm  mm  μm  nm  pm  fm  
mol  mmol  μmol  
MN  kN  N  
GΩ  MΩ  kΩ  Ω  mΩ  
GPa  MPa  kPa  hPa  Pa  
rad  mrad  
S  
s  ms  μs  ns  ps  fs  as  
sr  
Sv  mSv  µSv  
T  mT  µT  nT  
MV  kV  V  mV  μV  
GW  MW  kW  W  mW  μW  
kWb  Wb  mWb  μWb 