How to use
- Enter the first day of your last menstrual period.
- Adjust your usual cycle length if it is not 28 days.
- See your due date, weeks pregnant and milestones.
Frequently asked questions
How is the due date calculated?
It adds 280 days (40 weeks) to the first day of your last period, adjusted for cycle length. This is Naegele's rule, the method most doctors use before an ultrasound.
Is an ultrasound date more accurate?
Yes. An early ultrasound measurement is usually more accurate. If your doctor gave you a date from a scan, use that one.