D.C. Code § 37-201.18
The standard liquid gallon shall contain 231 cubic inches; the half gallon, one hundred and fifteen and five-tenths cubic inches; the quart, fifty-seven and seventy-five hundredths cubic inches; the pint, twenty-eight and eight hundred and seventy-five thousandths cubic inches; the half pint, fourteen and four hundred and thirty-seven thousandths cubic inches; the gill, seven and two hundred and eighteen thousandths cubic inches; the fluid ounce, one and eight-tenths cubic inches; and no liquid measure of other than the foregoing capacities, except multiples of the gallon, shall be deemed legal liquid measure in the District of Columbia; provided, that any automatic pump for the measurement of gasoline shall have graduations of fractional parts of a gallon in terms of either decimal or binary-submultiple subdivisions.
D.C. Code § 37-201.18