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Critical Care / ICU

P/F Ratio Calculator

Divide PaO₂ by FiO₂ to grade oxygenation.

PaO₂

mmHg

FiO₂

%

FORMULAPaO₂ ÷ (FiO₂ as a decimal)

Berlin categories assume PEEP ≥ 5 and the full clinical definition — interpret with the care team.

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Quick reference

What this calculator is for

The PaO₂/FiO₂ ratio grades oxygenation impairment and is part of the Berlin definition of ARDS.

Commonly used for

ARDS severity reference
Vent management discussions
ICU charting

Keep in mind

Berlin ARDS categories assume a minimum PEEP and the full clinical definition. Interpret alongside the care team’s assessment.

Education & reference only

Always verify calculations and clinical decisions with institutional protocols and qualified clinical judgment.

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