OpiCalc

989 Clinical Tools

APACHE II MAP Calculation OI (Oxygenation Index)PaO2/FiO2 Ratio (P/F)SAPS II SIRS Criteria SOFA Score qSOFA

OpiCalc

Open-access clinical infrastructure. Built to the standard every clinician deserves — fast, private, and free.

Zero data stored

Always free

Our mission & transparency

Get in Touch

Tool request, clinical feedback, or partnership inquiry — we read everything.

WhatsApp feedback

Partnership inquiry

© 2026 OpiCalc • Calculated Care

Protocols About Privacy Terms

PaO2/FiO2 Ratio (P/F)

PaO2/FiO2 (P/F) Ratio: The cornerstone of ARDS (Berlin) classification. Quantifies the severity of gas exchange impairment.

PaO2 (mmHg)

FiO2 (%)

Related Critical Care Tools

MAP Calculation

Glasgow Coma Scale

PaO2/FiO2 Ratio

Have feedback about this calculator?Let us know.