 In the typical adult, 1 litre of blood can hold about 200 mL of oxygen; 1 litre of dry air has about 210 mL of oxygen.Therefore, under these conditions, the ideal ventilation perfusion ratio would be about 0.95.If one were to consider humidified air (with less oxygen), then the ideal v/q ratio would be in the vicinity of 1.0, thus leading to concept of "ventilation-perfusion equality" or "ventilation-perfusion matching".