The arterial O2 tension/Fraction of inspired O2 ratio (PaO2/FiO2 ratio) is low in acute lung injury (<300), ARDS (<200), etc.

*FIO2 can be entered as a percentage or fraction.
Convert from FIO2 in L/min to %, following the equation:
FIO2 L/min = (FIO2 % - 21)/3
(1L/min = 24%, 2L/min = 27%, 3L/min = 30%, 4L/min = 33%, 5L/min = 36%, 6L/min = 39%)