Alveolar Gas Equation
Calculates expected alveolar oxygen pressure (PAO2).
RESULT
Alveolar Gas Equation
What is Alveolar Gas Equation?
Calculates expected alveolar oxygen pressure (PAO2). Alveolar Gas Equation is intended for use in: Adults.
How to Use the Alveolar Gas Equation Calculator
- Enter FiO2 in %.
- Enter PaCO2 in mmHg.
- Enter Atmospheric pressure (optional) in mmHg. Defaults to 760 mmHg (sea level)
- Enter Respiratory quotient (optional). Defaults to 0.8
- Click Calculate to see your result and interpretation.
Formula & Version
This calculator uses formula version 1.0, last reviewed September 2026.
References
- Standard respiratory physiology: PAO2 = FiO2 × (Patm − PH2O) − PaCO2/RQ
Frequently Asked Questions
What is Alveolar Gas Equation?
Calculates expected alveolar oxygen pressure (PAO2).
Who is Alveolar Gas Equation intended for?
Adults. Always confirm applicability to your specific patient before use.
What formula or reference does Alveolar Gas Equation use?
Standard respiratory physiology: PAO2 = FiO2 × (Patm − PH2O) − PaCO2/RQ
Is Alveolar Gas Equation a diagnosis?
No. Alveolar Gas Equation produces a score or estimate to support clinical decision-making — it is not a diagnosis and should be interpreted alongside full clinical judgement.
Medical Disclaimer: Medical calculators are provided for informational and educational purposes only. Results should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always verify results with a qualified healthcare professional.
