SI Prefixes
What Are They?
Prefixes are generally used to indicate orders of magnitude, and allow one to eliminate nonsignificant digits (i.e., 15,550 meters (m) becomes 15.55 kilometers (km)) and leading zeros in decial fractions (i.e., 0.00234 micrometers becomes 2.34 nanometers (nm)). Note that the prefixes larger than 1024 are not specified by SI.
|
Multiple
|
Prefix
|
Symbol
|
Common Name
|
|
(10100)100
|
anton
|
A
|
antonplex
|
|
(1010)100
|
-
|
-
|
googolplex
|
|
10100
|
-
|
-
|
googol
|
|
1024
|
yotta
|
Y
|
heptillion
|
|
1021
|
zetta
|
Z
|
hexillion
|
|
1018
|
exa
|
E
|
quintillion
|
|
1015
|
peta
|
P
|
quadrillion
|
|
1012
|
tera
|
T
|
trillion
|
|
109
|
giga
|
G
|
billion
|
|
106
|
mega
|
M
|
million
|
|
103
|
kilo
|
k
|
thousand
|
|
102
|
hecto
|
h
|
hundred
|
|
101
|
deca
|
da
|
ten
|
|
10-1
|
deci
|
d
|
tenth
|
|
10-2
|
centi
|
c
|
hundreth
|
|
10-3
|
milli
|
m
|
thousanth
|
|
10-6
|
micro
|
(Greek mu)
|
millionth
|
|
10-9
|
nano
|
n
|
billionth
|
|
10-12
|
pico
|
p
|
trillionth
|
|
10-15
|
femto
|
f
|
quadrillionth
|
|
10-21
|
zepto
|
z
|
hexillionth
|
|
10-24
|
yocto
|
y
|
heptillionth
|
