Pregnancy Due Date Calculator
Calculate your estimated due date, fetal development milestones, and current pregnancy progress.
Frequently Asked Questions About Due Date Calculation
How is a pregnancy due date calculated?
The most common and standard method to calculate a pregnancy due date is to add 280 days (40 weeks) to the first day of your Last Menstrual Period (LMP). If you have irregular cycles, knowing your exact conception date, IVF transfer date (Day 3 or Day 5), or getting an ultrasound measurement provides a much more accurate estimate.
How accurate is a pregnancy due date calculator?
A due date calculator provides a highly educated estimate to help you prepare. However, it is important to remember that only about 4% to 5% of babies are born on their exact due date. The vast majority of healthy babies arrive within a window between 37 and 42 weeks of gestation.
Can my due date change?
Yes, your healthcare provider might adjust your due date if a first-trimester ultrasound shows the baby is significantly larger or smaller than expected based on your LMP. Early ultrasounds are considered the most accurate method of dating a pregnancy.