Due Date Calculator

Calculate your estimated due date from your last menstrual period or conception date.

Enter Your Values

First Day of Last Menstrual Period

Average Cycle Length (days)

Results

Fill in your values above and click Calculate.

Frequently Asked Questions

Q.How is the due date calculated?

The standard method (Naegele's Rule) adds 280 days (40 weeks) to the first day of your last period. Only 5% of babies are born on their exact due date.

Q.What if my cycle is not 28 days?

For longer cycles, the due date is later. For shorter cycles, it's earlier. This calculator adjusts automatically for your cycle length.