The American Heritage® Dictionary of the English Language: Fourth Edition.
2000.
Conversion From U.S. Customary to Metric units.
When You Know
Multiply By
To Find
inches
25.4
millimeters
2.54
centimeters
feet
30.48
centimeters
yards
0.91
meters
miles
1.61
kilometers
teaspoons
4.93
milliliters
tablespoons
14.79
milliliters
fluid ounces
29.57
milliliters
cups
0.24
liters
pints
0.47
liters
quarts
0.95
liters
gallons
3.79
liters
cubic feet
0.028
cubic meters
cubic yards
0.76
cubic meters
ounces
28.35
grams
pounds
0.45
kilograms
short tons (2,000 lbs)
0.91
metric tons
square inches
6.45
square centimeters
square feet
0.09
square meters
square yards
0.84
square meters
square miles
2.60
square kilometers
acres
0.40
hectacres
From Metric to U.S. Customary Units
When You Know
Multiply By
To Find
millimeters
0.04
inches
centimeters
0.39
inches
meters
3.28
feet
1.09
yards
kilometers
0.62
miles
milliliters
0.20
teaspoons
0.06
tablespoons
0.03
fluid ounces
liters
1.06
quarts
0.26
gallons
4.23
cups
2.12
pints
cubic meters
35.32
cubic feet
1.35
cubic yards
grams
0.035
ounces
kilograms
2.21
pounds
metric ton (1,000 kg)
1.10
short ton
square centimeters
0.16
square inches
square meters
1.20
square yards
square kilometers
0.39
square miles
hectacres
2.47
acres
Temperature Conversion Between Celsius and Fahrenheit
°C = (°F - 32) ÷ 1.8
°F = (°C x 1.8) + 32
Condition
Fahrenheit
Celsius
Boiling point of water
212°
100°
A very hot day
104°
40°
Normal body temperature
98.6°
37°
A warm day
86°
30°
A mild day
68°
20°
A cool day
50°
10°
Freezing point of water
32°
0°
Lowest temperature Gabriel Fahrenheit could obtain by mixing salt and ice
0°
-17.8°
U.S. Customary System: Length
Unit
Relation to Other U.S. Customary Units
Metric Equivalent
inch
1/12 foot
2.54 centimeters
foot
12 inches or 1/3 yard
0.3048 meter
yard
36 inches or 3 feet
0.9144 meter
rod
16 1/2 feet or 5 1/2 yards
5.0292 meters
furlong
220 yards or 1/8 mile
0.2012 kilometer
mile (statute)
5,280 feet or 1,760 yards
1.6093 kilometers
mile (nautical)
2,025 yards
1.852 kilometers
U.S. Customary System: Volume or Capacity (Liquid Measure)
Unit
Relation to Other U.S. Customary Units
Metric Equivalent
ounce
1/16 pint
29.574 milliliters
gill
4 ounces
0.1183 liter
pint
16 ounces
0.4732 liter
quart
2 pints or 1/4 gallon
0.9463 liter
gallon
128 ounces or 8 pints
3.7853 liters
barrel
(wine)
31 1/2 gallons
119.24 liters
(beer)
36 gallons
136.27 liters
(oil)
42 gallons
158.98 liters
U.S. Customary System: Volume or Capacity (Dry Measure)
Unit
Relation to Other U.S. Customary Units
Metric Equivalent
pint
1/2 quart
0.5506 liter
quart
2 pints
1.1012 liters
peck
8 quarts or 1/4 bushel
8.8098 liters
bucket
2 pecks
17.620 liters
bushel
2 buckets or 4 pecks
35.239 liters
U.S. Customary System: Weight
Unit
Relation to Other U.S. Customary Units
Metric Equivalent
grain
1/7000 pound
64.799 milligrams
dram
1/16 ounce
1.7718 grams
ounce
16 drams
28.350 grams
pound
16 ounces
453.6 grams
ton (short)
2,000 pounds
907.18 kilograms
ton (long)
2,240 pounds
1,016.0 kilograms
U.S. Customary System: Geographic Area
Unit
Relation to Other U.S. Customary Units
Metric Equivalent
acre
4,840 square yards
4,047 square meters
Cooking Measures
Unit
Relation to Other Cooking Measures
Conversion to Metric Units
drop
1/76 teaspoon
0.0649 milliliter
teaspoon
76 drops or 1/3 tablespoon
4.9288 milliliters
tablespoon
3 teaspoons
14.786 milliliters
cup
16 tablespoons or 1/2 pint
0.2366 liter
pint
2 cups
0.4732
quart
4 cups or 2 pints
0.9463
British Imperial System: Volume or Capacity (Liquid Measure)
Unit
Relation to Other British Imperial Units
Conversion to U.S. Customary Units
Conversion to Metric Units
pint
1/2 quart
1.201 pints
0.5683 liter
quart
2 pints or 1/4 gallon
1.201 quarts
1.137 liters
gallon
8 pints or 4 quarts
1.201 gallons
4.546 liters
British Imperial System: Volume or Capacity (Dry Measure)
Unit
Relation to Other British Imperial Units
Conversion to U.S. Customary Units
Conversion to Metric Units
peck
1/4 bushel
1.0314 pecks
9.087 liters
bushel
4 pecks
1.0320 bushels
36.369 liters
Apothecary Weights
Unit
Relation to Other Apothecary Units
Conversion to U.S. Customary Units
Conversion to Metric Units
grain
160 dram or 1/5760 pound
equal to the U.S. Customary grain
64.799 milligrams
dram
60 grains or 1/8 ounce
2.1943 drams
3.8879 grams
ounce
8 drams
1.0971 ounces
31.1035 grams
pound
12 ounces or 96 drams
0.8232 pound
373.242 grams
Units of the International System
TheInternational System abbreviated SI, for Systeme International, the French name for the system) was adopted in 1960 by the 11th General Conference on Weights and Measures. An expanded and modified version of the metric system, International System addresses the needs of modern science for additional and more accurate units of measurement. The key features of the International System are decimalization, a system of prefixes, and a standard defined in terms of an invariable physical measure.
Base Units
The International System has base units from which all others in the system are derived. The standards for the base units, except for the kilogram, are defined by unchanging and reproducible physical occurences. For example, the meter is defined as the distance traveled by light in a vacuum in 1/299,792,458 of a second. The standard for the kilogram is a platinum-iridium cylinder kept at the International Bureau of Weights and Standards in Sèvres, France.
Unit
Quantity
Symbol
meter
length
m
kilogram
mass
kg
second
time
s
ampere
electric current
A
kelvin
temperature
K
mole
amount of matter
mol
candela
luminous intensity
cd
Supplementary Units
The International System uses two supplementary units that are based on abstract geometrical concepts rather than physical standards.
Unit
Quantity
Symbol
radian
plane angles
rad
steradian
solid angles
sr
Prefixes
A multiple of a unit in the International System is formed by adding a prefix to the name of that unit. The prefixes change the magnitude of the unit by orders of ten from 10
18
to 10
-18
.
Prefix
Symbol
Multiplying Factor
exa-
E
10
18
= 1,000,000,000,000,000,000
peta-
P
10
15
= 1,000,000,000,000,000
tera-
T
10
12
= 1,000,000,000,000
giga-
G
10
9
= 1,000,000,000
mega-
M
10
6
= 1,000,000
kilo-
K
10
3
= 1,000
hecto-
h
10
2
= 1000
deca-
da
10 = 10
deci-
d
10
-1
= 0.1
centi-
c
10
-2
= 0.01
milli-
m
10
-3
= 0.001
micro-
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
Additional Units
Listed below are a few of the non-SI units that are commonly used with the International System.
Unit
Quantity
Symbol
angstrom (= 10
-10
m)
length
Å
electron-volt (= 0.160 aJ)
energy
eV
hectare (= 10,000 m
2
)
land area
ha
liter (= 1.0dm
3
)
volume or capacity
l
standard atmosphere (= 101.3 kPa)
pressure
atm
Derived Units
Most of the units in the International System are derived units, that is units defined in terms of base units and supplementary units. Derived units can be divided into two groupsthose that have a special name and symbol, and those that do not.
those that have a special name and symbol, and those that do not.
