Calculator · Paediatrics

Corrected age (prematurity)

Chronological and corrected age for an infant born preterm.

What it is for

Interpreting development, growth charts and immunisation timing for premature babies (correct until ~2 years).

Use the working calculator

The working Corrected age (prematurity) calculator is on our calculators page. It is free and needs no account. Enter the values and it shows the result with the reading that goes with it.

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What you enter

The calculator asks for 3 items.

  • Date of birth (a date)
  • Gestation at birth — weeks (wks)
  • Gestation at birth — extra days (days)Optional.

How the result is read

The result is shown as Result. Formula: Corrected age = chronological age − (40 weeks − gestation at birth)

The calculator reports one of these readings, with the action that goes with it: Check the date; Born at term (; Corrected age below term-equivalent; Born preterm (.

Sources

These are the sources the calculator cites. Check the current version before relying on a threshold.

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For qualified clinicians. A score supports a clinical decision and does not make it: check the inputs, read the cited source, and use the tools in your clinical system for patient care where one is provided.