PHP Pregnancy Calculator

Although knowing the exact day your baby will be born is no exact science, even for your doctor, coming up with an estimated due date is. The estimated due date of a baby is calculated by adding 266 days to ovulation, or 280 days to the first day of the last menstrual cycle. Our pregnancy due date calculator lets you enter in the date of the first day of the last menstrual cycle. We then add 280 days to it using PHP to return the estimated due date.