International System of Units (SI)
SI Prefixes
Multiples
Factor
|
Name
|
Symbol
|
1024
|
yotta
|
Y
|
1021
|
zetta
|
Z
|
1018
|
exa
|
E
|
1015
|
peta
|
P
|
1012
|
tera
|
T
|
109
|
giga
|
G
|
106
|
mega
|
M
|
103
|
kilo
|
k
|
102
|
hecto
|
h
|
101
|
deka
|
da
|
|
|
|
|
Submultiplies
|
|
Factor
|
Name
|
Symbol
|
10−1
|
deci
|
d
|
10−2
|
centi
|
c
|
10−3
|
milli
|
m
|
10−6
|
micro
|
µ
|
10−9
|
nano
|
n
|
10−12
|
pico
|
p
|
10−15
|
femto
|
f
|
10−18
|
atto
|
a
|
10−21
|
zepto
|
z
|
10−24
|
yocto
|
y
|
Note: The kilogram is the only SI unit with a prefix as part of its name and symbol. Because multiple prefixes are not allowed, the kilogram and prefix names are used with the unit name gram and the prefix symbols are used with the unit symbol g. Other than in this case, any SI prefix may be used with any SI unit, including the degree Celsius and its symbol °C.
Example: 10–6 kg = 1 mg (one milligram),
but not 10–6 kg = 1 μkg (one microkilogram)
Source: National Institute of Standards and Technology (NIST)