PaO₂/FiO₂ (P/F)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
<300 = ARDS
About this calculator
The PaO2/FiO2 (P/F) calculator is a useful tool for healthcare professionals working in intensive care units. It helps calculate the ratio between arterial partial pressure of oxygen (PaO2) and fraction of inspired oxygen (FiO2) in patients.
This ratio is crucial in assessing the lung's capacity to oxygenate blood and identifying potential respiratory problems, such as acute respiratory distress syndrome (ARDS).
The PaO2/FiO2 calculator is a practical tool for doctors and nurses who need to make swift and accurate decisions in critical situations.
Additionally, the calculator also helps identify potential medication or ventilation errors, which is essential to ensure patient safety.
Frequently asked questions
What is the PaO2/FiO2 ratio?
The PaO2/FiO2 ratio is the ratio between arterial partial pressure of oxygen (PaO2) and fraction of inspired oxygen (FiO2) in patients.
When should I use the PaO2/FiO2 calculator?
The calculator should be used in intensive care units to assess the lung's capacity to oxygenate blood and identify potential respiratory problems.
What does a result of <300 mean?
A result of <300 indicates that the patient may be developing acute respiratory distress syndrome (ARDS).
Can I use the calculator if I'm not a healthcare professional?
No, it is recommended that only qualified healthcare professionals use the calculator to avoid misinterpretation of the results.