Nasal Oxygen FiO2 Estimate
Estimates the FiO2 for a patient on nasal oxygen whose FiO2 is not measured, as 0.21 plus 0.03 per liter per minute.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Oxygen flow by nasal cannula
- 3 L/min
Result: Estimated FiO2 0.30 (30%) at 3 L/min: 0.21 + 0.03 x 3, the estimate the 2024 Global Definition of ARDS uses when the FiO2 is not measured.
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Oxygen flow by nasal cannula
How this is calculated
Citation
Matthay MA et al. A New Global Definition of Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med. 2024;209(1):37-47 (Table 1). Wettstein RB et al. Delivered oxygen concentrations using low-flow and high-flow nasal cannulas. Respir Care. 2005;50(5):604-609. Read the sources: Matthay 2024 ↗, Wettstein 2005 ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.