Calculate your due date, track your pregnancy week by week, and discover important milestones on your journey to motherhood.
Average is 28 days. Enter your typical cycle length.
Enter your information to calculate your due date
Due date is calculated using Naegele's Rule: add 280 days (40 weeks) to the first day of your last menstrual period. This assumes a 28-day cycle with ovulation on day 14. Adjustments are made for different cycle lengths.
Only about 5% of babies are born on their exact due date. Most babies are born within 2 weeks before or after the estimated date. Early ultrasound dating (before 12 weeks) is generally most accurate.
First trimester (weeks 1-12): Major organ development. Second trimester (weeks 13-27): Rapid growth, movement felt. Third trimester (weeks 28-40): Final development, preparation for birth.
A baby is full term at 39-40 weeks. Early term is 37-38 weeks, late term is 41 weeks, and post-term is 42+ weeks. Most healthy deliveries occur between 37-42 weeks.