Prefix
|
Symbol
|
1000m
|
10n
|
Decimal
|
Short scale
|
Long scale
|
Since[n 1]
|
yotta
|
Y
|
10008
|
1024
|
1,000,000,000,000,000,000,000,000
|
Septillion
|
Quadrillion
|
1991
|
zetta
|
Z
|
10007
|
1021
|
1,000,000,000,000,000,000,000
|
Sextillion
|
Trilliard
|
1991
|
exa
|
E
|
10006
|
1018
|
1,000,000,000,000,000,000
|
Quintillion
|
Trillion
|
1975
|
peta
|
P
|
10005
|
1015
|
1,000,000,000,000,000
|
Quadrillion
|
Billiard
|
1975
|
tera
|
T
|
10004
|
1012
|
1,000,000,000,000
|
Trillion
|
Billion
|
1960
|
giga
|
G
|
10003
|
109
|
1,000,000,000
|
Billion
|
Milliard
|
1960
|
mega
|
M
|
10002
|
106
|
1,000,000
|
Million
|
1960
|
kilo
|
k
|
10001
|
103
|
1000
|
Thousand
|
1795
|
hecto
|
h
|
10002/3
|
102
|
100
|
Hundred
|
1795
|
deca
|
da
|
10001/3
|
101
|
10
|
Ten
|
1795
|
|
10000
|
100
|
1
|
One
|
–
|
deci
|
d
|
1000−1/3
|
10−1
|
0.1
|
Tenth
|
1795
|
centi
|
c
|
1000−2/3
|
10−2
|
0.01
|
Hundredth
|
1795
|
milli
|
m
|
1000−1
|
10−3
|
0.001
|
Thousandth
|
1795
|
micro
|
μ
|
1000−2
|
10−6
|
0.000001
|
Millionth
|
1960
|
nano
|
n
|
1000−3
|
10−9
|
0.000000001
|
Billionth
|
Milliardth
|
1960
|
pico
|
p
|
1000−4
|
10−12
|
{0.000000000001
|
Trillionth
|
Billionth
|
1960
|
femto
|
f
|
1000−5
|
10−15
|
0.000000000000001
|
Quadrillionth
|
Billiardth
|
1964
|
atto
|
a
|
1000−6
|
10−18
|
0.000000000000000001
|
Quintillionth
|
Trillionth
|
1964
|
zepto
|
z
|
1000−7
|
10−21
|
0.000000000000000000001
|
Sextillionth
|
Trilliardth
|
1991
|
yocto
|
y
|
1000−8
|
10−24
|
0.000000000000000000000001
|
Septillionth
|
Quadrillionth
|
1991
|
- ↑ The metric system was introduced in 1795 with six prefixes. The other dates relate to recognition by a resolution of the CGPM.
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