A-a Gradient

Calculate the alveolar-arterial oxygen gradient.

A-a = PAO2 − PaO2

FiO2 (%)

Barometric Pressure (mmHg)

PaCO2 (mmHg)

PaO2 (mmHg)

Disclaimer: These calculators are for educational and clinical decision support only. Always verify calculations and apply clinical judgment. Not a substitute for professional medical advice.