(LEGACY) Fenton 2003 Growth calculator for preterm infants

Uses the older 2003 Fenton growth charts to report percentiles and Z-scores on growth metrics.

Please be aware that the newer 2013 Fenton growth charts are available


Citing: If you use PediTools for a publication or clinical guideline, please consider citing: Chou JH et al., J Med Internet Res 2020;22(1):e16204 (available open access [PDF])

Growth Parameters
Gestational age
Weight (grams)
Head circumference (cm)
Length (cm)



Optional helper calculators


Gestational Age Calculator
Date of birth
Gestational age at birth
Date of measurement
Postmenstrual age...

Unit Conversion
inches= ... cm
cm= ... inches
pounds ounces= ... grams
grams= ... pounds ... ounces



Tips and Tricks

  • Gestational age, enter in the form of ## #/7; e.g., 30 3/7 for 30 weeks and 3 days gestation
  • Weight: grams are assumed. To enter pounds and ounces, enter #-#; e.g., 8-4 for 8 pounds and 4 ounces
  • Head circumference or length: cm are assumed. To enter inches, enter #"; e.g., 20" for 20 inches

Based on