| 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
| 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 groups those that have a special name and symbol, and those that do not. |
| |
| Without Names and Symbols |
| Measure of |
Derivation |
| acceleration |
m/s
2
|
| angular acceleration |
rad/s
2
|
| angular velocity |
rad/s |
| density |
kg/m
3
|
| electric field strength |
V/m |
| luminance |
cd/m
2
|
| magnetic field strength |
A/m |
| velocity |
m/s |
| |
| With Names and Symbols |
| Unit |
Measure of |
Symbol |
Derivation |
| coulomb |
electric charge |
C |
A·s |
| farad |
electric capacitance |
F |
A·s/V |
| henry |
inductance |
H |
V·s/A |
| hertz |
frequency |
Hz |
cycles/s |
| joule |
quantity of energy |
J |
N·m |
| lumen |
flux of light |
lm |
cd·sr |
| lux |
illumination |
lx |
lm/m
2
|
| newton |
force |
N |
kg·m/s
2
|
| ohm |
electric resistance |
 |
V/A |
| pascal |
pressure |
Pa |
N/m
2
|
| tesla |
magnetic flux density |
T |
Wb/m
2
|
| volt |
voltage |
V |
W/A |
| watt |
power |
W |
J/s |
| weber |
magnetic flux |
Wb |
V·s |
|
| |
| The American Heritage® Dictionary of the English Language, Fourth Edition. Copyright © 2000 by Houghton Mifflin Company. Published by the Houghton Mifflin Company. All rights reserved. |
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