16 CFR 500.8 - Units of weight or mass and measure.
(a) Statements of weight or mass shall be in terms of both avoirdupois pound and ounce and SI metric kilograms, grams, or milligrams. (Examples of avoirdupois/metric declarations: “Net Wt 15 oz (425 g)” or “Net Wt 1 1/2 lbs (680 g)” or “ 2.5 oz (70.8 g)”; examples of metric/avoirdupois declarations: “Net Mass 425 g (15 oz)” or “Net Mass 680 g (1 1/2 lbs)” or “100 g e (3.5 oz).”)
(b) Statements of fluid measure shall be in terms of both the U.S. gallon of 231 cubic inches and quart, pint, and fluid ounce subdivisions thereof and SI metric liters or milliliters and shall (except in the case of petroleum products, for which the declaration shall express the volume at 60 °Fahrenheit (15.6 °Celsius)) express the volume at 68 °Fahrenheit (20 °Celsius). (Examples of gallon/metric declarations: “Net 12 fl oz (354 mL)” or “Net Contents 1 gal (3.78 L)” or “8 fl oz (236 mL)”; examples of metric/gallon declarations: “Net 500 mL (1.05 pt)” or “Net Contents 1 L (1.05 qt).”)
(c) Statements of linear measure shall be in terms of both yards, feet, and inches and SI metric meters, centimeters, or millimeters.
(d) Statements of measure of area shall be in terms of both square yards, square feet, and square inches and SI metric square meters, square decimeters, square centimeters, or square millimeters.
(e) Statements of dry measure shall be in terms of both the U.S. bushel of 2,150.42 cubic inches and peck, dry quart, and dry pint subdivisions thereof and SI metric liters or milliliters.
(f) Statements of cubic measure shall be in terms of both cubic yard, cubic foot, and cubic inch and SI metric cubic meters, cubic decimeters, or cubic centimeters.