A-a Gradient Calculator

Calculator Pro Zone

Important: This calculator is for educational purposes only. Always consult with healthcare professionals for clinical decisions.

Note: The A-a gradient helps assess the efficiency of oxygen transfer from alveoli to arterial blood.

PaO2 (mmHg)

FiO2 (Fraction of Inspired Oxygen)

PaCO2 (mmHg)

Age (years)

Altitude (feet above sea level)

Clinical Setting Body Temperature (°C) Hemoglobin (g/dL)

A-a Gradient:

Expected A-a Gradient:

Alveolar PO2 (PAO2):