Modern practice often uses cuffed tubes with careful pressure monitoring; follow local protocol.

Pediatric ETT Size

Pediatrics Emergency Medicine Critical Care

Medical context

Estimate pediatric endotracheal tube internal diameter and approximate oral insertion depth from age.

Pediatric teams must confirm age-appropriate references and weight-based dosing with local protocols.

This page explains the Peds ETT formula, how to interpret the output, known limitations, and peer-reviewed references so you can verify results against primary sources and local protocols.

It is grouped under Pediatrics because neonatal and pediatric medical calculators.

How to use this calculator

Enter the values requested by the Peds ETT calculator using the units shown beside each field.
Review the calculated result and read the interpretation section before acting on the output.
Check limitations and references if the result will change management, dosing, or disposition.
Use the related calculators section when you need supporting values (for example electrolytes, weight, or complementary risk scores).

Calculator

Age (years)Tube type

Result

5 mm ID

Approx. oral depth 14 cm at lips

Uncuffed ≈ age/4 + 4; cuffed ≈ age/4 + 3.5. Confirm with clinical sizing and institution.

Educational use only. Confirm results with clinical judgment, primary sources, and local protocols. Not a substitute for professional medical advice. Full disclaimer.

Formula

Uncuffed ID ≈ age/4 + 4; cuffed ID ≈ age/4 + 3.5. Oral depth (cm) ≈ age/2 + 12.

Interpretation

Starting size only — adjust for leak, auscultation, and age-specific airway anatomy.

Limitations

Formulas are less reliable in neonates and adolescents; follow local airway carts.

Frequently asked questions

Cuffed or uncuffed?: Modern practice often uses cuffed tubes with careful pressure monitoring; follow local protocol.
Is the Peds ETT result enough to make a treatment decision?: No. Calculators support medical decision-making but do not replace examination, shared decision-making, institutional protocols, or consultant input when stakes are high.
Does Calcmedical store the values I type in?: Inputs are processed in your browser for this session. We do not ask for patient names or medical record numbers. See our privacy policy for hosting and analytics details.

References

Standard pediatric airway sizing formulas