CO₂ content (also known as "Total CO₂") is a blood test that usually appears on a "Chem 19" or an electrolyte panel. The value measures the total dissolved Carbon dioxide (CO₂) in blood. It is determined by combining the Bicarbonate (HCO₃^-) and the partial pressure of CO₂ multiplied by a factor which estimates the amount of pure CO₂ that is dissolved in its natural form (usually 0.03).