Welcome to the Fenton Preterm Growth Chart site
“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, China, Columbia, Costa Rica, Croatia, France, Germany, India, Iran, Italy, Korea, Mexico, Peru, Portugal, Russia, Saudi Arabia, Singapore, Spain, Taiwan, Thailand, The Netherlands, and The USA
Are endorsed by: the French, Portuguese, and Colombian Pediatric Societies
NEW! - A Preterm Growth Chart App using the Fenton growth charts is now available in the Apple iStore for Apple iPhones and iPads that have an Operating System of iOS 8 or greater.
Please see the App page for details.
New! - 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 R Tanis, Kim H Jae. 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: http://www.biomedcentral.com/1471-2431/13/92
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 summarize 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 confidence that you need this precision.
1. Actual Age Calculator v6 (July 11, 2014) - 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 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 (June 2014). Many thanks to Dr. Tim Stevens for his assistance in preparation of this spreadsheet.
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.
DO NOT ENTER DAYS OF AGE INTO THIS CALCULATOR AS IT CAUSES THIS CALCULATOR TO INCORRECTLY ROUND UP OR DOWN.
Research data 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: firstname.lastname@example.org