Clinical tools

Pulmonology Calculators

Pulmonology calculators cover original BODE scoring in stable established COPD, paired pleural-fluid classification, alveolar oxygen and gas-exchange arithmetic, oxygenation ratios and indices, HFNC response-monitoring arithmetic, and cumulative smoking exposure. Similar respiratory measurements can serve different clinical questions.

Keep serum and pleural-fluid studies appropriately paired, preserve support, inspired-gas, altitude, timing, and ventilation assumptions for gas-exchange and HFNC calculations, and use BODE only with its standardized stable-COPD source measurements.

Tools by task

Gas exchange & oxygenation

Gas-exchange and oxygenation arithmetic, including paired observations during HFNC support.

A–a Gradient Calculator (Alveolar–Arterial Oxygen Gradient)Calculate the A–a oxygen gradient from paired arterial PaO₂ and PaCO₂, FiO₂, and explicit pressure and R assumptions, with limited historical age-reference context.P/F Ratio Calculator (PaO₂/FiO₂)Calculate arterial PaO₂/FiO₂ ratio with explicit PaO₂ and FiO₂ units, FiO₂ reliability guidance, and ARDS definition limits.Oxygenation Index (OI) CalculatorCalculate conventional Oxygenation Index from matched FiO₂, ventilator mean airway pressure, and arterial PaO₂ during invasive mechanical ventilation.ROX Index CalculatorCalculate the adult HFNC ROX Index from SpO₂, explicit FiO₂, and respiratory rate for a single assessment or a 2-, 6-, and 12-hour trend.

Pleural fluid

Classic Light criteria for paired serum and pleural-fluid studies.

Light's Criteria Calculator for Pleural EffusionCalculate all three classic Light criteria from paired serum and pleural-fluid protein and LDH values, with exact strict boundaries and optional pseudoexudate gradient context.

COPD

Original BODE scoring in clinically stable, established COPD.

BODE Index Calculator for COPDCalculate the original Celli 2004 BODE Index for clinically stable, established COPD from BMI, post-bronchodilator FEV₁ % predicted, mMRC dyspnea, and 6-minute walk distance.

Smoking exposure

Cumulative pack-years from smoking amount and duration.

Pack YearsPack-Year Calculator – Cigarette Smoking HistoryCalculate cigarette pack-years across one or more smoking-history periods using cigarettes/day or standardized 20-cigarette packs/day and years smoked.

Important limits

These calculations do not establish a diagnosis, identify a cause, or determine screening eligibility, procedures, referral, or treatment.
Preserve the stated measurement, sampling, timing, and clinical-context requirements; arithmetic does not replace clinical assessment.

Review standards Read the disclaimer Report a correction

Emergency Medicine & Critical Care Calculators Cardiology Calculators General Medicine Calculators Nephrology Calculators