5 Pulmonology Calculators – Oxygenation & Gas Exchange
Pulmonology calculators cover alveolar oxygen and gas-exchange arithmetic, oxygenation ratios and indices, and cumulative smoking exposure. Similar oxygen variables serve different formulas and clinical questions.
Choose the page that matches the available FiO₂, arterial gas, pressure, and ventilation data. Keep values at an appropriate common time point and preserve the required measurement context.
All medical calculatorsSources and review processMedical disclaimer
Choose a calculator by task
Use the task groups below to find the calculator whose formula, intended population, required measurements, and purpose match the task.
Gas exchange and oxygenation
Select A–a gradient, alveolar gas, P/F ratio, or oxygenation index according to the measured gases, FiO₂, and airway-pressure information available.
Smoking-exposure history
Calculate cumulative pack-years from smoking amount and duration without assigning screening eligibility.
How to choose a calculator in this category
- Use the A–a gradient, alveolar gas equation, P/F ratio, and oxygenation index only for the distinct question and input set each formula specifies.
- Oxygenation index requires the stated mechanical-ventilation and mean-airway-pressure context.
- Pair FiO₂, PaO₂, PaCO₂, and pressure measurements from an appropriate clinical time point rather than combining unrelated observations.
Important limits
- Gas-exchange arithmetic does not diagnose a pulmonary disorder or determine oxygen or ventilator settings.
- Altitude, inspired-gas composition, sampling, timing, and ventilation context can materially affect interpretation.
- Pack-years is exposure arithmetic and does not determine screening eligibility, diagnosis, or treatment.