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SI metric conversion factors

The following conversion factors are taken from the SPE Metric Standard. The complete standard can be found on the SPE website.

Units in alphabetical order and conversion factors

(symbols of SI units given in parentheses)

٭٭See footnote.

References

1. Since 1893, the U.S. basis of length measurement has been derived from metric standards. In 1959, a small refinement was made in the definition of the yard to resolve discrepancies both in this country and abroad, which changed its length from 3600/3937 m to 0.9144 m exactly. This resulted in the new value being shorter by two parts in a million. At the same time, it was decided that any data in feet derived from and published as a result of geodetic surveys within the U.S. would remain with the old standard (1 ft=1200/3937 m) until further decision. This foot is named the U.S. survey foot. As a result, all U.S. land measurements in U.S. customary units will relate to the meter by the old standard. All the conversion factors in these tables for units referenced to this footnote are based on the U.S. survey foot, rather than the international foot. Conversion factors for the land measure given below may be determined from the following relationships:
 1 league=3 miles (exactly) 1 rod=16½ ft (exactly) 1 chain=66 ft (exactly) 1 section=1 sq mile 1 township=36 sq miles
2. This value was adopted in 1956. Some of the older International Tables use the value 1.055 04 E+03. The exact conversion factor is 1.055 055 852 62* E+03
3. The exact conversion factor is 1.638 706 4*E−05.
4. This sometimes is called the moment of inertia of a plane section about a specified axis.
5. In 1964, the General Conference on Weights and Measures adopted the name “liter” as a special name for the cubic decimeter. Prior to this decision, the liter differed slightly (previous value, 1.000 028 dm3), and in expression of precision volume measurement, this fact must be kept in mind.
6. Not the same as reservoir “perm.”
7. Not the same dimensions as “millidarcy-foot.”
8. The exact conversion factor is 4.535 923 7*E−01.
9. The exact conversion factor is 4.448 615 260 5*E+00.
10. Torque unit; see text discussion of “Torque and Bending Moment.”
11. Torque divided by length; see text discussion of “Torque and Bending Moment.”
12. Defined (not measured) value.