Tidal Volume by Predicted Body Weight

Target tidal volume for lung-protective ventilation, dosed to predicted body weight rather than actual weight.

Formula

Tidal volume = mL/kg target × Predicted body weight (Devine formula)

Result

Limitations

• Dosed to predicted, not actual, body weight — this is intentional for lung-protective ventilation, since lung size tracks height and sex, not actual weight.
• 6 mL/kg PBW is the standard lung-protective starting point; the 4–8 mL/kg range exists to allow titration for plateau pressure and patient comfort, not as an independently 'safe' range at every value.
• Achieving a target tidal volume doesn't guarantee a safe plateau pressure — both should be checked together.

References

• The Acute Respiratory Distress Syndrome Network. Ventilation with Lower Tidal Volumes as Compared with Traditional Tidal Volumes for Acute Lung Injury and the Acute Respiratory Distress Syndrome. NEJM 2000.