Clinical Tools
Fast, accurate calculators designed for bedside use and NBRC exam prep. All formulas match NBRC standards.
Blood gas & oxygenation
InstrumentPurposeComputes · inputs
- ABG InterpreterpH → PaCO₂ → HCO₃⁻ → PaO₂Full acid-base analysis with anion gap, P/F ratio and A-a gradientpH → PaCO₂ → HCO₃⁻ → PaO₂pH · PaCO₂ · HCO₃⁻ · PaO₂ · FiO₂ · Na⁺ · Cl⁻
- P/F RatioPaO₂ ÷ FiO₂ · ≤100 / ≤200 / ≤300ARDS severity classification by Berlin DefinitionPaO₂ ÷ FiO₂ · ≤100 / ≤200 / ≤300PaO₂ · FiO₂
- A-a GradientPAO₂ − PaO₂ · normal ≈ age ÷ 4 + 4Alveolar-arterial oxygen difference with age-adjusted normal rangePAO₂ − PaO₂ · normal ≈ age ÷ 4 + 4FiO₂ · PaCO₂ · PaO₂ · age
- FiO₂ Estimator21% + ~4% per L/min (NC)Estimate delivered FiO₂ from O₂ delivery device and flow rate21% + ~4% per L/min (NC)device · L/min
Ventilation & weaning
InstrumentPurposeComputes · inputs