Texas Natural Resources Code - NAT RES § 91.052. Definition

(a) The term “cubic foot of gas” or “standard cubic foot of gas” means the volume of gas contained in one cubic foot of space at a standard pressure base and at a standard temperature base.

(b) The standard pressure base shall be 14.65 pounds per square inch absolute, and the standard temperature base shall be 60 degrees Fahrenheit. If the conditions of pressure and temperature differ from this standard, conversion of the volume from these conditions to the standard conditions shall be made in accordance with the ideal gas laws, corrected for deviation.