ISO Units & Symbols
|
QUANTITY |
NAME |
SYMBOL |
|
length |
metre |
m |
|
mass |
kilogram |
kg |
|
time |
second |
s |
|
electric current |
ampere |
A |
|
thermodynamic temperature |
kelvin |
K |
|
amount of substance |
mole |
mol |
|
luminous intensity |
candela |
cd |
|
QUANTITY |
NAME |
SYMBOL |
|
plane angle |
radian |
Rad |
|
solid angle |
steradian |
sr |
|
QUANTITY |
NAME |
SYMBOL |
EXPRESSION |
|
frequency |
hertz |
Hz |
1 Hz = 1 s-1 |
|
force |
newton |
N |
1 N = I kg·m/s2 |
|
pressure |
Pascal |
Pa |
1 Pa = 1 N/m2 |
|
energy, work, |
joule |
J |
1 J = 1 N·m |
|
power |
watt |
W |
1 W = 1 J/s |
|
electric charge, |
coulomb |
C |
1 C = 1 A·s |
|
electric potential, |
volt |
V |
1 V = 1 J/C |
|
electric capacitance |
farad |
F |
1 F = I C/V |
|
electric resistance |
ohm |
Ω |
1 Ω = 1 V/A |
|
electric conductance |
siemens |
S |
1 S = 1Ø-1 |
|
flux of magnetic induction, |
weber |
Wb |
1 Wb = 1 V·s |
|
magnetic flux density, |
tesla |
T |
1 T = 1 Wb/m2 |
|
inductance |
henry |
H |
1 H = 1 Wb/A |
|
luminous flux |
lumen |
lm |
1 Im = 1 cd·sr |
|
illuminance |
lux |
Ix |
1 Ix = 1 lm/m2 |
|
PREFIX |
SYMBOL |
FACTOR |
|
tera |
T |
1012 1 000 000 000 000 |
|
giga |
G |
109 1000 000 000 |
|
mega |
M |
106 1000 000 |
|
kilo |
k |
103 1000 |
|
hecto |
h |
102 100 |
|
deca |
da |
101 10 |
|
deci |
d |
10-1 0.1 |
|
centi |
c |
10-2 0.01 |
|
milli |
m |
10-3 0.001 |
|
micro |
11 |
10-6 0.000 001 |
|
nano |
n |
10-9 0.000 000 001 |
|
Pico |
p |
10-12 0.000 000 000 001 |
|
femto |
f |
10-15 0.000 000 000 000 001 |
|
atto |
a |
10-18 0.000 000 000 000 000 001 |
Derived Units Without Special Names
|
QUANTITY |
UNIT NAME |
UNIT |
|
area |
square metre |
m2 |
|
volume |
cubic metre |
m3 |
|
speed, velocity |
metre per second |
m/s |
|
acceleration |
metre per second squared |
m/s2 |
|
specific volume |
cubic metre per kilogram |
m3/kg |
|
density, mass density |
kilogram per cubic metre |
kg/m3 |
|
luminance |
candela per square metre |
cd/m2 |
|
thermal conductivity |
watt per metre kelvin |
W/ (m× K) |
|
specific energy |
joule per kilogram |
J/kg |
Acceptable Non SI Units
|
QUANTITY |
NAME |
SYMBOL |
DEFINITION |
|
time |
minute |
min |
1 min = 60 s |
|
|
hour |
h |
1 h = 60 min = 3600 s |
|
|
day |
d |
1 d = 24 h = 86400 s |
|
plane angle |
degree |
° |
1° = 1 (π/180) rad |
|
|
minute |
' |
1' (1/60)° = 2.909 x 10-4 rad |
|
|
second |
" |
1" (1/60)' = 4.848 x 10-6 rad |
|
volume |
litre |
l |
1l = 1 dm3 = 10-3 m3 |
|
mass |
tonne |
t |
1 t = 1 Mg = l03 kg |