Desired Minute Ventilation Calculator
The minute ventilation and rate needed to move an arterial CO₂ to a target — the classic bedside correction formula, with its assumptions and limits stated.
Written by Apex Respiratory Editorial Team
Enter the current rate, tidal volume, current PaCO₂, and desired PaCO₂ to calculate the minute ventilation and rate to set.
Reading the correction
PaCO₂ varies inversely with alveolar (and, with dead space constant, minute) ventilation, so to halve the CO₂ you roughly double the ventilation.
You can reach the target V̇E by changing rate, tidal volume, or both — this tool holds VT constant and gives the rate.
The relationship is approximate and breaks down at high rates: expiratory time shortens (gas trapping / auto-PEEP) and dead space blunts the gain. In ARDS keep VT lung-protective and adjust the rate, watching plateau pressure and auto-PEEP — or accept permissive hypercapnia.
Educational use only. This material supports respiratory therapy education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or physician orders. Always follow facility policies and current provider orders, and verify calculations independently before clinical use.
Sources
- Kacmarek RM, Stoller JK, Heuer AJ. Egan's Fundamentals of Respiratory Care. 12th ed. Elsevier; 2021.
- Hess DR, Kacmarek RM. Essentials of Mechanical Ventilation. 4th ed. McGraw-Hill; 2019.