The Metric Conversion Act of 1975, as amended by the Omnibus Trade and Competitiveness Act of 1988 (15 U.S.C. 205) and implemented by Executive Order 12770, states that:
The metric system is the preferred measurement system for U.S. trade and commerce.
The metric system of measurement will be used, to the extent economically feasible, in Federal agencies' procurements, grants, and other business-related activities.
Metric implementation is not required if such use is likely to cause significant inefficiencies or loss of markets to United States firms.
Recipients are encouraged to use the metric system to the maximum extent practicable in measurement-sensitive activities and in measurement-sensitive outputs resulting from DOE funded programs.