Alveolar-Arterial Gradient (A-a Gradient) Calculator is a respiratory tool commonly applied in Pulmonology. Calculates alveolar oxygen tension and A-a gradient from atmospheric pressure, FiO2, PaCO2, and PaO2, with age-adjusted expected gradient. Use the interactive calculator for inputs, limitations, and primary references.

Not a substitute for clinical judgment. Verify critical values with primary literature, local protocols, and specialist input when appropriate.