Pediatric ETT Size Calculator

Estimates pediatric endotracheal tube internal diameter by age or height and gives neonatal weight guidance.

Inputs

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

Equation and Work

Equation:
Solving steps:
Age-based ID
—
mm
Height-based ID
—
mm
Neonate guide
—
mm ID
Normal/reference: For children >1 year, calculated ID is rounded to the nearest 0.5 mm. Neonate guide: <1000 g: 2.5 mm; 1000–2000 g: 3.0 mm; 2000–3000 g: 3.5 mm; >3000 g: 4.0 mm.

Clinical Significance

Pediatric ETT size estimates internal diameter from age or height. In the age equation, 16 and 4 are the standard pediatric sizing constants; in the height equation, 20 converts height in centimeters into an approximate tube ID in millimeters.

Provides starting estimates; clinicians commonly prepare tubes 0.5 mm above and below the calculated size.

Tube selection is patient-specific. Use local airway policy, cuffed/uncuffed context, and bedside assessment.

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.