The following tables appeared in the January 2007 issue of the Energy Information Administration’s Monthly Energy Review. The Energy Information Administration is a statistical agency of the U.S. Department of Energy.
Table 1 Metric Conversion Factors
These metric conversion factors can be used to calculate the metric-unit equivalents of values expressed in U.S. Customary units. For example, 500 short tons are the equivalent of 453.6 metric tons (500 short tons X 0.9071847 metric tons/short ton = 453.6 metric tons).
Type of Unit | U.S. Unit | Equivalent in Metric Units | ||
Mass | 1 short ton (2,000 lb) | = | 0.907 184 7 | metric tons (t) |
1 long ton | = | 1.016 047 | metric tons (t) | |
1 pound (lb) | = | 0.453 592 37^{a} | kilograms (kg) | |
1 pound uranium oxide (lb U^{3}O^{s}) | = | 0.384 647^{b} | kilograms uranium (kgU) | |
1 ounce, avoirdupois (avdp oz) | ^{=} | 28.349 52 | grams (g) | |
Volume | 1 barrel of oil (bbl) | = | 0.158 987 3 | cubic meters (m^{3}) |
1 cubic yard (yd^{3}) | = | 0.764 555 | cubic meters (m^{3}) | |
1 cubic foot (ft^{3}) | = | 0.028 316 85 | cubic meters (m^{3}) | |
1 U.S. gallon (gal) | = | 3.785 412 | liters (L) | |
1 ounce, fluid (fl oz) | = | 29.573 53 | milliliters (mL) | |
1 cubic inch (in^{3}) | = | 16.387 06 | milliliters (mL) | |
Length | 1 mile (mi) | = | 1.609 344^{a} | kilometers (km) |
1 yard (yd) | 0.914 4^{a} | meters (m) | ||
1 foot (ft) | = | 0.304 8^{a} | meters (m) | |
1 inch (in) | = | 2.54^{a} | centimeters (cm) | |
Area | 1 acre | = | 0.404 69 | hectares (ha) |
1 square mile (mi^{2}) | = | 2.589 988 | square kilometers (km^{2}) | |
1 square yard (yd^{2}) | = | 0.836 127 4 | square meters (m^{2}) | |
1 square foot (ft^{2}) | = | 0.092 903 04^{a} | square meters (m^{2}) | |
1 square inch (in^{2}) | = | 6.451 6^{a} | square centimeters (cm^{2}) | |
Energy | 1 British thermal unit (Btu)^{c} | = | 1,055.055 852 62^{a} | joules (J) |
1 calorie (cal) | = | 4.186 8^{a} | joules (J) | |
1 kilowatthour (kWh) | = | 3.6^{a} | megajoules (MJ) | |
Temperature^{d} | 32 degrees Fahrenheit (°F) | = | 0^{a} | degrees Celsius (°C) |
212 degrees Fahrenheit (°F) | = | 100^{a} | degrees Celsius (°C) |
^{a}Exact conversion.
Calculated by the Energy Information Administration.
^{c}The Btu used in this table is the International Table Btu adopted by the Fifth International Conference on Properties of Steam, London, 1956.
^{d}To convert degrees Fahrenheit (°F) to degrees Celsius (°C) exactly, subtract 32, then multiply by 5/9.
Notes: • Spaces have been inserted after every third digit to the right of the decimal for ease of reading. • Most metric units belong to the International System of Units (SI), and the liter, hectare, and metric ton are accepted for use with the SI units.
Table 2 Metric Prefixes
The names of multiples and subdivisions of any unit may be derived by combining the name of the unit with prefixes as below.
Unit Multiple | Prefix | Symbol | Unit Subdivision | Prefix | Symbol |
10^{1} | deka | da | 10-^{1} | deci | D |
10^{2} | hecto | h | 10 ” ^{2} | centi | c |
10^{3} | kilo | k | 10 -^{3} | milli | m |
10^{6} | mega | M | 10 – ^{6} | micro | n |
10^{9} | giga | G | 10 -^{9} | nano | n |
1012 | tera | T | 10 -^{12} | pico | ^{p} |
10^{15} | peta | P | 10 -^{15} | femto | f |
10^{18} | exa | E | 10 -^{18} | atto | a |
10^{21} | zetta | Z | 10 -^{21} | zepto | z |
10^{24} | yotta | Y | 10 -^{24} | yocto | ^{y} |
Table 3 Other Physical Conversion Factors
The factors below can be used to calculate equivalents in various physical units commonly used in energy analyses. For example, 10 barrels are the equivalent of 420 U.S. gallons (10 barrels x 42 gallons/barrel = 420 gallons).
Energy Source | Original Unit | Equivalent in Final Units | ||
Petroleum | 1 barrel (bbl) | = | 42^{a} | U.S. gallons (gal) |
Coal | 1 short ton | = | 2,000^{a} | pounds (lb) |
1 long ton | = | 2,240^{a} | pounds (lb) | |
1 metric ton (t) | = | 1,000^{a} | kilograms (kg) | |
Wood | 1 cord (cd) | = | 1.25^{b} | shorts tons |
1 cord (cd) | = | 128^{a} | cubic feet (ft^{3}) |
^{a}Exact conversion.
Calculated by the Energy Information Administration.