Breath-by-breath Volume of Carbon dioxide VCO2 Calculation The amount of carbon dioxide produced as a result of metabolism in designated as VCO2. It may be reported in mL/min or mL/kg/min. At standard temperature and pressure, the rate at which carbon dioxide enters the alveolar gas from the blood is equal to the metabolic production of carbon dioxide by tissue metabolism in the body. This calculator helps the VCO2 calculation of true Breath-by-Breath systems Formula Used: VCO2 (mL/min) = VE (FECO2- FICO2) VCO2(mL/kg/min) = VCO2 (mL/min)/kg body weight Variable Definitions: VCO2 = CO2 exhaled in mL/min VE = Volume of air expired in mL/min FECO2 = Fraction of CO2 in expired air FICO2 = Fraction of CO2 in inspired air VCO2 calculation of true Breath-by-Breath systems is made easier. Free online medical calculators.