Step 2: Convert to Metabolic Rate VO 2 = Volume of Oxygen Consumed FlO 2 = Fraction of Oxygen in influent Air CALCULATE FEO 2 = Fraction of Oxygen in Effluent Air DAY 1, 08:28 PROARESS: 46% Use the drop-down menus on the Cacculation screen to your ngin to that choose then cilick CALCULATE. .