S. I. Metric
Systeme International Metric
Basic Units
Quantity
Name of Unit
Symbol
length
metre
m
mass
gram
g
time
second
s
temperature
celcius
oC
electric current
ampere
A
amount of substance
mole
mol
luminous intensity
candela
cd
volume
litre
L
Derived Units
Force   ( kg•m/s2 )
Newton
N
Pressure  ( N/m2 )
Pascal
Pa
Energy  ( Nm )
Joule
J
Frequency ( 1/s )
Hertz
Hz
Power ( J/s )
Watt
W
Electric charge ( A/s )
Coulomb
C
Electric potential ( J/C )
Volt
V
Electric resistance ( V/A )
ohm
Ω
Luminous flux
Lumen
lm
Prefixes
Prefix Name
Prefic Symbol
Value
yotta
Y
1000 000 000 000 000 000 000 000
=1024
zetta
Z
1000 000 000 000 000 000 000
=1021
exa
E
1000 000 000 000 000 000
= 1018
peta
P
1000 000 000 000 000
= 1015
terra
T
1000 000 000 000
= 1012
giga
G
1000 000 000
= 109
mega
M
1000 000
= 106
kilo
k
1000
= 103
hecta
h
100
= 102
deca
da
10
= 101
----
----
1
= 100
deci
d
0.1
= 10-1
centi
c
0.01
= 10-2
milli
m
0.001
= 10-3
micro
μ
0.000 001
= 10-6
nano
n
0.000 000 001
= 10-9
pico
p
0.000 000 000 001
= 10-12
femto
f
0.000 000 000 000 001
= 10-15
atto
a
0.000 000 000 000 000 001
= 10-18
zepto
z
0.000 000 000 000 000 000 001
= 10-21
yocto
y
0.000 000 000 000 000 000 000 001
= 10-24