Pediatric ETT Size Calculator
Enter patient age and weight to get the recommended ETT internal diameter, cuffed/uncuffed options, insertion depth at lips, and cuff pressure guidance.
Use the Pediatric ETT Size Calculator
Patient Parameters
Enter age and weight to generate ETT recommendations.
Formula Reference
| Tube type | Formula (ID mm) |
|---|---|
| Uncuffed (>1 yr) | (age/4) + 4 |
| Cuffed (>1 yr) | (age/4) + 3.5 |
| Depth at lip | 3 × ID (mm) cm |
| Depth (age-based) | (age/2) + 12 cm |
| Cuff pressure | 20–25 cmH2O |
Enter patient age and weight, then click Calculate ETT Size.
Recommended ETT
Uncuffed
Smaller
mm ID
Primary
mm ID
Larger
mm ID
Cuffed
Smaller
mm ID
Primary
mm ID
Larger
mm ID
Depth & Cuff Pressure
Depth at lip (3× ID)
cm
Depth at lip (age-based)
cm
Cuff pressure target
20–25
cmH2O
Clinical Notes
Clinical reference only. ETT sizes are estimates based on population formulas. Always have one size above and below available. Confirm placement with waveform capnography, bilateral breath sounds, and chest X-ray. Decisions must be made by a qualified clinician.
Summary
Enter patient age and weight to get the recommended ETT internal diameter, cuffed/uncuffed options, insertion depth at lips, and cuff pressure guidance.
How it works
- Enter the patient's age in years (use decimals for months, e.g. 0.5 for 6 months) and weight in kg.
- The calculator applies standard age-based formulas to derive the recommended uncuffed ETT internal diameter (ID).
- A cuffed tube recommendation is also shown (typically 0.5 mm smaller than the uncuffed equivalent).
- Insertion depth at the lip is estimated using the 3× tube ID rule and an age-based alternative so you can cross-check.
- Cuff pressure guidance (target 20–25 cmH2O) and a reminder to confirm placement with waveform capnography are displayed.
- Review adjacent sizes — one above and one below — before preparing your equipment.
Use cases
- Rapid equipment sizing during pediatric resuscitation.
- Anesthesia pre-op planning for pediatric surgical patients.
- PICU and NICU airway management reference.
- Paramedic and transport-team preparation for pediatric airways.
- Medical student and resident education on ETT sizing formulas.
- Simulation and training scenarios for pediatric airway skills.
Frequently Asked Questions
Last updated: 2026-09-20 ·
Reviewed by Nham Vu