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PaO2/FiO2 Ratio Calculator (P/F Ratio)

mmHg
(0.21 - 1.0)
Enter as a decimal (e.g., 0.21 for 21%, 0.50 for 50%).

Explore our suite of respiratory calculators designed to simplify pulmonary assessments. From evaluating oxygenation via the PaO2/FiO2 Ratio to predicting lung capacity, these tools assist medical professionals and individuals in understanding respiratory health. Get quick, accurate results for vital metrics.

Formula:

PaO2/FiO2 Ratio Formula

The PaO2/FiO2 Ratio, also known as the P/F Ratio, is a simple index used to assess the severity of lung injury and oxygenation efficiency. It is calculated as:

P/F Ratio = PaO₂ / FiO₂

  • PaO₂: Partial pressure of oxygen in arterial blood (in mmHg)
  • FiO₂: Fraction of inspired oxygen (expressed as a decimal, e.g., 0.21 for room air, 1.0 for 100% oxygen)

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