are in 1 cubic foot of gas at 80 °F and gauge pressure 50 psi? (assuming that there is 13.6 psi atmospheric pressure and ignoring super compressibility) Vs = 1 cu ft × [(13.6 psi + 50 psi) / 14.73 psi] × [(60 °F + 459.67 °F) / (80 °F + 459.67 °F)] Vs = 4.16 scf See also Standard conditions for temperature and pressure References Units of amount of substance