Units of Measure and Measurement Notation
The language of science depends on the proper use of units of measure and measurement notation. The
following tables list the names and symbols for many of the common units. Most units used in high
school science courses come from or are derived from Le Système International d'Unités (SI). Many
aspects of SI overlap with the metric system. More common in this country for general use (but not in
science classes) is the English system, which includes such measures as the inch, foot, mile, BTU, ounce,
quart, gallon, pound, ton, psi, and the Fahrenheit temperature scale. Also included in this section is a
listing of the Greek alphabet. Greek letters are commonly used in scientific notation.
Base SI Units
Quantity
Name
Symbol
length
mass
meter
kilogram
m
kg
time
second
s
amount of substance
mole
mol
temperature
Kelvin
K
electric current
ampere
A
luminous intensity
candela
cd
SI Prefixes
Prefix
Symbol
Multiply root word by
gigamega-
G
M
1,000,000,000 (109)
1,000,000 (106)
kilo-
k
1000
hecto-
h
100
deca-
da
10
deci-
d
0.1
centi-
c
0.01
milli-
m
0.001
0.000001 (10−6)
micronano-
n
0.000000001 (10−9)
pico-
p
0.000000000001 (10−12)
SI Derived Units
Quantity
Name
Symbol
area
volume
square meter
cubic meter
m2
m3
speed
meter per second
m/s or m s−1
density
kg/m3 or kg m−3
concentration
kilogram per cubic
mole permeter
cubic meter
mol/m3 or mole m−3
force
newton
N
pressure
pascal
Pa (N/m2)
energy, work, heat
joule
J
electrical potential
volt
V
electrical resistance
ohm
Non-SI Units
Quantity
time
volume
density
temperature
pressure
concentration
energy
Name
minute
hour
day
liter
milliliter
gram per milliliter
degree Celsius
atmosphere
torr
millimeter of mercury
inches of mercury
bar
millibar
mole per liter
calorie
Calorie (kilocalorie)
Symbol
min
h
d
L
mL
g/mL
o
C
atm
torr
mm Hg
in Hg
b
mb
mol/L
c
C
The Greek Alphabet
Greek
upper case
Greek lower
case
Name
Latin
Sound
alpha
A a
drama
beta
B b
baby
gamma
G g, ng
ganglion
delta
D d
deep
epsilon
E e
epic
zeta
Z z
adze
eta
E e
they
theta
Th th
atheist
iota
I i
intrigue
kappa
K k
crisp
lambda
L l
look
mu
M m
meter
nu
N n
ant
xi
X x
axe
omicron
O o
obey
pi
P p
poem
rho
Rh rh, r
catarrh
Greek
upper case
Greek lower
case
Name
Latin
Sound
sigma
S s
sport
tau
T t
tote
upsilon
Y y, u
abyss
phi
Ph ph
Philip
chi
Ch ch
character
psi
Ps ps
apse
omega
O o
ocean