Poiseuille Equation Calculator

Estimates how airway or tube radius changes the driving pressure needed to maintain flow.

Inputs

Color mode links each input to the matching equation term and solving arithmetic.

Equation and Work

Equation:
Solving steps:
New ΔP₂
—
cmH₂O
r₁⁴
—
mm⁴
r₂⁴
—
mm⁴

Clinical Significance

Estimates how airway or tube radius changes the driving pressure needed to maintain flow.

This calculator expands that idea by identifying the relevant measured values, substituting the selected inputs, and carrying the arithmetic through in the solving steps.

Demonstrates how narrowing an airway or ETT markedly increases driving pressure/work of breathing because radius is raised to the fourth power.

This simplified form assumes constant flow, length, and viscosity and is intended for comparison rather than direct ventilator management.

References (APA 7th Edition)

  1. Chang, D. W. (2020). Respiratory Care Calculations (Revised 4th ed.). Jones & Bartlett Learning. Formula content adapted from the uploaded text/reference packet.