NRP 9th-edition methodology

Neonatal ETT Size& Depth Calculator

Estimate an uncuffed neonatal endotracheal tube size and starting oral insertion depth from current weight and corrected gestational age, with every method and disagreement kept visible.

Weight + gestationUpper-gum depth landmark2026 evidence review

Educational clinical decision support for trained professionals. This tool provides initial equipment-preparation estimates. It does not confirm tracheal placement, final depth, or suitability for an individual airway.

Neonatal airway preparation

Estimate ETT size and starting oral depth

Enter current weight and corrected gestational age. Weight and gestation are calculated independently so disagreement stays visible.

Patient inputs

Weight and corrected gestation

Clinical context

Add alternative-airway context

Calculated locally in your browserNo patient data uploadedEvery sizing method displayed

Equipment selection

Neonatal ETT size by weight and gestation

The calculator applies weight and corrected gestational age independently. If the two pathways disagree, it displays both instead of concealing the conflict with a single larger-tube recommendation.

Current weightGestational ageUncuffed ETT ID
<800 g22–25 weeks2.5 mm*
800–1,200 g26–28 weeks2.5 mm
1,201–2,200 g29–34 weeks3.0 mm
>2,200 g>34 weeks3.5 mm

*A 2.0-mm ID tube may be considered in an extremely small infant when available and supported by local protocol. It is not displayed as the routine default.

Starting oral depth

Measure from the correct landmark

The NRP 9th-edition values are presented at the anterior edge of the upper gum at the midline. The calculator also displays weight + 6 cm and optional nasal-tragus length + 1 cm as independent estimates. It flags a difference greater than 0.5 cm instead of averaging discordant methods.

Corrected gestationCurrent weightUpper-gum mark
<23 weeks<500 g5.0–5.5 cm
23–24 weeks500–600 g5.5 cm
25–26 weeks700–800 g6.0 cm
27–29 weeks900–1,000 g6.5 cm
30–32 weeks1,100–1,400 g7.0 cm
33–34 weeks1,500–1,800 g7.5 cm
35–37 weeks1,900–2,400 g8.0 cm
38–40 weeks2,500–3,100 g8.5 cm
41–43 weeks3,200–4,200 g9.0 cm

Depth is not placement confirmation

Neonatal tracheas are short, and head movement can change tip position. Immediately confirm ventilation and tracheal placement; reassess after securing, movement, transport, or unexplained deterioration. Imaging remains part of final depth assessment when indicated.

Alternative airway

When an SGA or laryngeal mask is an option

≥34 weeks

A laryngeal mask is a guideline-supported alternative when face-mask ventilation is unsuccessful and may be considered as a primary interface in selected settings.

Compressions

An ETT is recommended. In an infant at least 34 weeks, an SGA may be reasonable when intubation is unsuccessful or not feasible.

<34 weeks or <2 kg

Evidence is insufficient for a routine recommendation. Device availability and manufacturer labeling vary; use local neonatal guidance.

Frequently asked questions

Neonatal ETT sizing and insertion depth

What size ETT is used for a newborn?

Current neonatal selection uses weight and gestational age together. NRP 9th-edition starting bands use 2.5-mm tubes through approximately 1,200 g, 3.0 mm from about 1,201–2,200 g, and 3.5 mm above 2,200 g, with gestational-age bands shown separately.

Are neonatal endotracheal tubes cuffed?

Uncuffed tubes remain the routine starting style during neonatal resuscitation. Cuffed or 4.0-mm tubes may be considered for specific indications but are not the routine default.

How is neonatal ETT insertion depth estimated?

The calculator leads with the corrected-gestational-age table and shows weight plus 6 cm and optional nasal-tragus length plus 1 cm as independent cross-checks. The result is a starting estimate, not confirmation of final position.

Where is neonatal ETT depth measured?

This calculator labels the NRP 9th-edition starting depth at the anterior edge of the upper gum at the midline. Older resources may describe a lip landmark, so the measurement point must be checked before comparing values.

When can a laryngeal mask be used in neonatal resuscitation?

For newborns at least 34 weeks, a laryngeal mask or other SGA is a guideline-supported alternative when face-mask ventilation is unsuccessful. During chest compressions, an ETT is preferred; an SGA may be reasonable when intubation is unsuccessful or not feasible.

Can the calculator confirm correct ETT placement?

No. Tube passage, clinical response, chest movement, bilateral breath sounds, exhaled carbon dioxide when appropriate, and imaging according to the setting/local protocol are used to confirm placement and final depth.

Evidence base

Current guidance, primary evidence, and device labeling

Evidence and links reviewed August 28, 2026. NRP is a program of the American Academy of Pediatrics; PulmTools is independent and does not claim AAP, AHA, NRP, Intersurgical, or Teleflex endorsement.

AHA/AAP — 2025 Neonatal Resuscitation GuidelinesCurrent neonatal resuscitation guidance, including alternative-airway and laryngeal-mask recommendations.AAP/AHA — Textbook of Neonatal Resuscitation, 9th EditionCurrent NRP reference for neonatal ETT equipment selection and starting insertion-depth tables.Peebles et al. — ETT Size Adjustments Within Seven Days of Neonatal IntubationMulticenter registry study of 7,293 neonatal intubations supporting revised attention to size-transition boundaries.ANZCOR Guideline 13.5 — Tracheal Intubation and Ventilation of the NewbornPractical neonatal size, corrected-gestation/current-weight depth, and confirmation guidance.Intersurgical — i-gel official size and weight guidanceManufacturer weight bands for device-specific supraglottic-airway sizing.Teleflex — LMA Supreme user guideManufacturer weight bands and instructions for LMA Supreme sizing.

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