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Centile Calculator

Our centile calculators produce customised birthweight centiles using the principles of the GROW (Gestation Related Optimal Weight) method. See References and Related Literature for further information.

The calculators are continually being updated for different populations and countries, depending on the availability of databases from which coefficients can be derived.

The tools are free and available as one of two types of applications:

  • Individual centile calculator (ICC) - for day-to-day use, to calculate birthweight centiles one at a time. Available currently as a web based application for the following countries: Australia, Brazil, Germany, India, Ireland, Italy, Netherlands, New Zealand, Spain, Sweden, United Kingdom and United States. Please note that an updated version, based on 122 countries and regions, is under development and will replace the current version.
  • Bulk centile calculator (BCC) - to derive multiple centiles for research or audit purposes. A new version (v8.0.4) has been released, developed in Excel spreadsheet format for over 130 countries, ethnic groups and regions. BCC description.

To receive a centile calculator, please contact us

  1. Name, affiliation, and brief note about the intended use (clinical, audit, or area of research), to help us keep refining these applications
  2. Type of calculator required (individual or bulk).

Is your country not represented? We welcome anonymised databases to derive coefficients for additional countries / populations. Please contact us


GROW software makes calculations on the basis of published principles and formulae, and is released only after rigorous testing for quality assurance.
However Gestation Network or the Perinatal Institute cannot accept responsibility for clinical diagnoses or decisions made on the basis of the software. For more information, see our terms and conditions of use.


© Gestation Network 2019