Calculate your estimated due date based on the first day of your last menstrual period (LMP) or your date of conception.
The most common method for calculating a due date is **Naegele's rule**. This rule assumes a regular 28-day menstrual cycle and that conception occurs on the 14th day. The calculation is done by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP).
How accurate is the due date calculator?
An estimated due date is just that—an estimate. Only about 5% of babies are born on their exact due date. It is a helpful guide for you and your healthcare provider, but labor can naturally start anytime between 38 and 42 weeks.
What if I have an irregular cycle?
If your menstrual cycles are not a typical 28 days, the LMP method may be less accurate. The most accurate way to determine a due date in this case is through an early ultrasound, which measures the baby's size. Always consult with your healthcare provider.