Gestational age calculator for preterm infants
Enter any available dates, ages, or gestations, and other values will be calculated.
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])
Today is Friday, December 6th, 2024
Instructions and notes:
- Enter any known values. All possible other values will be calculated. Values that can not be calculated will be left blank.
- Dates are interpreted semi-intelligently, but be aware of possible errors if unrecognized formats are used.
- The due date is 40 weeks after the last menstrual period, or 38 weeks after conception (implantation / fertilization).
- On the date of birth, a baby is on the first day of life (day of life 1), but is zero days old.
- The first exam for retinopathy of prematurity is at 31 weeks postmenstrual age, but not before 4 weeks of age (typically indicated if born at <31 weeks gestation or birth weight <1,500 grams).