# Appendix B. metric and other physical conversion factors.

Data presented in the Monthly Energy Review and in other Energy Information Administration publications are expressed predominately in units that historically have been used in the United States, such as British thermal units, barrels, cubic feet, and short tons. However, because U.S. commerce involves other nations, most of which use metric units of measure, the U.S. Government is committed to the transition to the metric system, as stated in the Metric Conversion Act of 1975 (Public Law 94-168), amended by the Omnibus Trade and Competitiveness Act of 1988 (Public Law 100-418), and Executive Order 12770 of July 25, 1991.

The metric conversion factors presented in Table B1 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).

In the metric system of weights and measures, the names of multiples and subdivisions of any unit may be derived by combining the name of the unit with prefixes, such as deka, hecto, and kilo, meaning, respectively, 10, 100, 1,000, and deci, centi, and milli, meaning, respectively, one-tenth, one-hundredth, and one-thousandth. Common metric prefixes can be found in Table B2.

The conversion factors presented in Table B3 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).
```Table B1. Metric Conversion Factors

multiplied
Type of Unit U.S. Unit by

Mass short tons (2,000 lb) x
long tons x
pounds (lb) x
pounds uranium oxide (lb
[U.sub.3] [O.sub.8]) x
ounces, avoirdupois (avdp oz) x

Volume barrels of oil (bbl) x
cubic yards ([yd.sup.3]) x
cubic feet ([ft.sup.3]) x
U.S. gallons (gal) x
ounces, fluid (fl oz) x
cubic inches ([in.sup.3]) x

Length miles (mi) x
yards (yd) x
feet (ft) x
inches (in) x

Area acres x
square miles ([mi.sup.2]) x
square yards ([yd.sup.2]) x
square feet ([ft.sup.2]) x
square inches ([in.sup.2]) x

Temperature degrees Fahrenheit
([degrees] F) x

Energy British thermal units (Btu) x
calories (cal) x
Kilowatthours (kWh) x

Conversion
Type of Unit U.S. Unit Factor

Mass short tons (2,000 lb) 0.907 184 7
long tons 1.016 047
pounds (lb) .453 592 37 (a)
pounds uranium oxide (lb
[U.sub.3] [O.sub.8]) 0.384 647 (b)
ounces, avoirdupois (avdp oz) 28.349 52

Volume barrels of oil (bbl) 0.158 987 3
cubic yards ([yd.sup.3]) 0.764 555
cubic feet ([ft.sup.3]) 0.028 316 85
U.S. gallons (gal) 3.785 412
ounces, fluid (fl oz) 29.573 53
cubic inches ([in.sup.3]) 16.387 06

Length miles (mi) 1.609 344 (a)
yards (yd) 0.914 4 (a)
feet (ft) 0.304 8 (a)
inches (in) 2.54 (b)

Area acres 0.404 69
square miles ([mi.sup.2]) 2.589 988
square yards ([yd.sup.2]) 0.836 127 4
square feet ([ft.sup.2]) 0.092 903 04 (a)
square inches ([in.sup.2]) 6.451 6 (b)

Temperature degrees Fahrenheit 5/9 (after subtracting
([degrees] F) 32) (a,c)

Energy British thermal units (Btu) 1,055.055 852 62 (a,d)
calories (cal) 4.186 8 (a)
Kilowatthours (kWh) 3.6 (a)

Type of Unit U.S. Unit equals

Mass short tons (2,000 lb) =
long tons =
pounds (lb) =
pounds uranium oxide (lb
[U.sub.3] [O.sub.8]) =
ounces, avoirdupois (avdp oz) =

Volume barrels of oil (bbl) =
cubic yards ([yd.sup.3]) =
cubic feet ([ft.sup.]) =
U.S. gallons (gal) =
ounces, fluid (fl oz) =
cubic inches ([in.sup.3]) =

Length miles (mi) =
yards (yd) =
feet (ft) =
inches (in) =

Area acres =
square miles ([mi.sup.2]) =
square yards ([yd.sup.2]) =
square feet ([ft.sup.2]) =
square inches ([in.sup.2]) =

Temperature degrees Fahrenheit
([degrees] F)

Energy British thermal units (Btu) =
calories (cal) =
Kilowatthours (kWh) =

Type of Unit U.S. Unit Metric Unit

Mass short tons (2,000 lb) metric tons (t)
long tons metric tons (t)
pounds (lb) kilograms (kg)
pounds uranium oxide (lb
[U.sub.3] [O.sub.8]) kilograms uranium (kgU)
ounces, avoirdupois (avdp oz) grams (g)

Volume barrels of oil (bbl) cubic meters ([m.sup.3])
cubic yards ([yd.sup.3]) cubic meters ([m.sup.3])
cubic feet ([ft.sup.]) cubic meters ([m.sup.3])
U.S. gallons (gal) liters (L)
ounces, fluid (fl oz) milliliters (mL)
cubic inches ([in.sup.3]) milliliters (mL)

Length miles (mi) kilometers (km)
yards (yd) meters (m)
feet (ft) meters (m)
inches (in) centimeters (cm)

Area acres hectares (ha)
square miles ([mi.sup.2]) square kilometers
([km.sup.2])
square yards ([yd.sup.2]) square meters
([m.sup.2])
square feet ([ft.sup.2]) square meters
([m.sup.2])
square inches ([in.sup.2]) square centimeters
([cm.sup.2])

Temperature degrees Fahrenheit degrees Celsius
([degrees] F) ([degrees] C)

Energy British thermal units (Btu) joules (J)
calories (cal) joules (J)
Kilowatthours (kWh) megajoules (M J)

(a) Exact conversion.

(b) Calculated by the Energy Information Administration.

(c) To convert degrees Celsius ([degrees] C) to degrees Fahrenheit
([degrees] F) exactly, multiply by 9/5, then add 32.

(d) The Btu used in this table is the International Table Btu
adopted by the Fifth International Conference on Properties of
Steam, London, 1956.

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. For more
information about the SI units, contact Dr. Barry Taylor at Building
221, Room B610, National Institute of Standards and Technology,
Gaithersburg, MD 20899, or on telephone number 301-975-4220.

Sources: * General Services Administration, Federal Standard 376B,
Preferred Metric Units for General Use by the Federal Government
(Washington, DC, January 27, 1993), pp. 9-11, 13, and 16. * National
Institute of Standards and Technology, Special Publications 330, 811,
and 814. * American National Standards Institute/Institute of
Electrical and Electronic Engineers, ANSI/IEEE Std 268-1992, pp. 28
and 29.
Table B2. Metric Prefixes

Unit Unit
Multiple Prefix Symbol Subdivision Prefix Symbol

[10.sup.1] deka da [10.sup.-1] deci d
[10.sup.2] hecto h [10.sup.-2] centi c
[10.sup.3] kilo k [10.sup.-3] milli m
[10.sup.6] mega M [10.sup.-6] micro [micro]
[10.sup.9] giga G [10.sup.-9] nano n
[10.sup.12] tera T [10.sup.-12] pico p
[10.sup.15] peta P [10.sup.-15] femto f
[10.sup.18] exa E [10.sup.-18] atto a
[10.sup.21] zetta Z [10.sup.-21] zepto z
[10.sup.24] yotta Y [10.sup.-24] yocto y

Source: U.S. Department of Commerce, National Institute of Standards
and Technology, The International System of Units (SI), NIST Special
Publication 330, 1991 Edition (Washington, DC, August 1991), p.10.
Table B3. Other Physical Conversion Factors

multiplied Conversion
Energy Source Original Unit by Factor equals

Petroleum barrels (bbl) x 42 (a) =

Coal short tons x 2,000 (a) =
long tons x 2,240 (a) =
metric tons (t) x 1,000 (a) =

Wood cords (cd) x 1.25 (b) =
cords (cd) x 128 (a) =

Energy Source Original Unit Final Unit

Petroleum barrels (bbl) U.S. gallons (gal)

Coal short tons pounds (lb)
long tons pounds (lb)
metric tons (t) kilograms (kg)

Wood cords (cd) shorts tons
cords (cd) cubic feet ([ft.sup.3])

(a) Exact conversion.

(b) Calculated by the Energy Information Administration.

Source: U.S. Department of Commerce, National Institute of Standards
and Technology, Specifications, Tolerances, and Other Technical
Requirements for Weighing and Measuring Devices, NIST Handbook 44,
1994 Edition (Washington, DC, October 1993), pp. B-10, C-17 and
C-21.
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