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“The Fenton growth chart for preterm infants has been revised to accommodate the World Health Organization Growth Standard and reflect actual age instead of completed weeks, in order to improve preterm infant growth monitoring.”
Editor, BMC Pediatrics

These growth charts:
Are: “commonly used in NICUs today” -  American Academy of Pediatrics 2014 Nutrition Handbook 

Are being used in the following countries: Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, China, Colombia, Costa Rica, Croatia, France, Germany, India, Indonesia, Iran, Israel, Italy, Korea, Mexico, New Zealand, Peru, Poland, Portugal, Russia, Saudi Arabia, Singapore, Spain, Sweden, Taiwan, Thailand, the Netherlands, the UK, and the USA
Are endorsed by: the French, Portuguese and Colombia Neonatal/Pediatric Societies and the Ecuador Ministry of Public Health
Here is a list of countries from which people have accessed this webpage: Download country list

Three Preterm Growth Chart Apps using the Fenton growth charts are now available. Please see the App page for details.
Preterm growth charts with large "Boy" and "Girl" labels for easy identification
  - print well in colour or black and white

  - To download PDFs of Colour growth CHARTS to print or save for later printing click here:
 2013 Preterm Growth Chart for Girls - to use in colour or black & white
 2013 Preterm Growth Chart for Boys - to use in colour or black & white

To download PDFs of growth CHARTS without the large gender labels:    
2013 Preterm Growth Chart for Girls
2013 Preterm Growth Chart for Boys
A free copy of the development ARTICLE for the 2013 growth chart can be found online at:
Fenton, Tanis R & Kim, Jae H. A systematic review and meta-analysis to revise the Fenton growth chart for preterm infants. BMC Pediatrics.2013, 13:59

Growth chart validation study #1:
Fenton TR, Nasser R, Eliasziw M, Kim JH, Bilan D, Sauve R. Validating the weight gain of preterm infants between the reference growth curve of the fetus and the term infant. BMC Pediatr. 2013;13(1):92. Free download:

Chose the correct calculator for your use:  
The differences between the calculators are due to different approaches to the data, i.e. different summaries of the data in the background. The calculator chosen should be based on the form of the anthropometric data you have  (is the data completed weeks or actual age?). The use of completed weeks is historic, when the data was only collected with weekly precision.  When whole weeks are entered into the two calculators, the calculators give different values  (e.g. 32 weeks 0 days) - this is not an error.
Completed weeks is how most research data is collected, that is when only the whole weeks gestational age data is available (24 0/7 to 24 6/7 is summarized as 24 weeks). The completed weeks calculator uses data that has summarized all the size of all the babies that were born that week.
The Actual age calculator data has been adjusted to allow for daily charting in electronic growth charts, and the database has an individual data values for each day. The data was adjusted as documented in our 2013 paper to produce the actual age version, and the daily values were obtained from the splined data curves. The actual age calculator should only be used if you have weeks and days of gestational age, and if you are confident that you need this precision. 

NEW! - The calculators now include SD23 correction for extreme weight z-scores, to improve accuracy of extreme values. While assessment revealed minimal differences with the SD23 correction, we wanted to follow the WHO's lead to provide the most accurate extreme z-scores as possible [1]. Head circumference and length were normally distributed throughout these charts so no correction was needed.
WHO Multicentre Growth Reference Study Group. WHO Child Growth Standards: Length/height-for-age, weight-for-age, weight-for-length, weight-for-height and body mass index-for-age: Methods and development. Geneva: World Health Organization, 2006 p 302.

1. Actual Age Calculator v8 (April 3, 2017)  - Use only if age is defined in both weeks and days - if age is defined only as weeks, use the completed weeks calculator, below. To download the excel calculator that will allow you to calculate exact percentiles and z-scores for infants with age defined in both days and weeks, for up to 20 babies at a time, click here: 
Clinical actual age percentile and z-score calculator

2. Research Bulk Calculator - Uses Completed weeks for weight, Head circumference, and Length - can calculate up to 500 babies' completed weeks z-scores and exact percentiles at one time (April 3, 2017).
Many thanks to Dr. Tim Stevens for his assistance in preparation of these spreadsheets. 
These results differ from the Actual Age Calculator since they are based on Completed weeks (24 weeks and 0 to 6 days are categorized as 24 weeks), which is usually of utility for research purposes. 
Research data completed weeks Fenton 2013 weight calculator - wt, L, HC 
3. A web-based size-for-gestational age and gestational-age calculator:
4. A smart phone app (free)

 If you need the Growth Chart Data for electronic charting or other reasons, please send me an email at: 
Best regards,