PaO₂/FiO₂ Ratio
P/F ratio for oxygenation assessment.
What this calculator does
This tool calculates the ratio of arterial oxygen pressure (PaO₂) to the fraction of inspired oxygen (FiO₂). The P/F ratio is a simple measure of how well the lungs are oxygenating the blood.
What your result means
Lower ratios can indicate worse oxygenation. The value is used in critical care and research. Your care team will interpret it in context with your condition and other tests.
This is not medical advice. A healthcare provider should interpret results in your context.
PaO₂ (mmHg)
FiO₂ (decimal)
Key terms
- PaO₂/FiO₂ ratio
- Ratio of arterial oxygen pressure to inspired oxygen fraction; a simple measure of oxygenation.
- PaO₂
- Arterial partial pressure of oxygen.
- FiO₂
- Fraction of inspired oxygen.
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This tool is for educational and reference use only. It does not constitute medical advice. Always consult a healthcare professional for medical decisions.