PaO2/FiO2 Ratio
Classifies ARDS severity (Berlin criteria).
What is PaO2/FiO2 Ratio?
Classifies ARDS severity (Berlin criteria). PaO2/FiO2 Ratio is intended for use in: Adults.
How to Use the PaO2/FiO2 Ratio Calculator
- Enter PaO2 in mmHg.
- Enter FiO2 in %.
- Click Calculate to see your result and interpretation.
Formula & Version
This calculator uses formula version 1.0, last reviewed September 2026.
Clinical Considerations & Limitations
- Full Berlin ARDS classification also requires bilateral opacities on chest imaging not explained by another cause, and PEEP ≥ 5 cmH2O — this calculator only classifies the oxygenation ratio.
References
- ARDS Definition Task Force, JAMA 2012;307:2526-2533 (Berlin definition)
Frequently Asked Questions
What is PaO2/FiO2 Ratio?
Classifies ARDS severity (Berlin criteria).
Who is PaO2/FiO2 Ratio intended for?
Adults. Always confirm applicability to your specific patient before use.
What are the limitations of PaO2/FiO2 Ratio?
Full Berlin ARDS classification also requires bilateral opacities on chest imaging not explained by another cause, and PEEP ≥ 5 cmH2O — this calculator only classifies the oxygenation ratio.
What formula or reference does PaO2/FiO2 Ratio use?
ARDS Definition Task Force, JAMA 2012;307:2526-2533 (Berlin definition)
Is PaO2/FiO2 Ratio a diagnosis?
No. PaO2/FiO2 Ratio produces a score or estimate to support clinical decision-making — it is not a diagnosis and should be interpreted alongside full clinical judgement.
