Due date calculator
Tap the first day of your last period to see your estimated due date, your week and your trimester on one calendar. Nothing is stored.
Tap the day your last period started
Not sure? Pick your best guess. You can change it any time.
November 2026
Common questions
How is the due date worked out?
It is 280 days (40 weeks) after the first day of your last period, moved earlier or later if your cycle is shorter or longer than 28 days. It is an estimate: babies are not all born on their due date, and term runs from 37 to 42 weeks.
What if my cycle is longer or shorter than 28 days?
Change the cycle length under the calendar. A longer cycle moves the date a little later and a shorter one a little earlier. If your cycles vary a lot, the date is less certain, and your clinician may adjust it.
Does the ultrasound date replace this one?
If a clinician has given you a due date from a scan, follow theirs. This calculator uses only the date you enter, and your clinician may adjust the date after a scan.
These calculators give general estimates for learning and planning, not medical advice. Talk to your clinician about your health.