Pregnancy Due Date Calculator
Calculate your estimated due date and see how far along you are in your pregnancy. Enter the first day of your last period or conception date to get your timeline and key milestones.
How We Calculate This
Uses Naegele's rule: Due date = LMP + 280 days. For conception date: Due date = conception + 266 days. Weeks pregnant calculated from LMP to current date.
Frequently Asked Questions
How is the due date calculated?
The due date is calculated as 280 days (40 weeks) from the first day of your last menstrual period (LMP). This assumes a 28-day cycle with ovulation on day 14.
How accurate is the due date?
Only about 5% of babies are born on their due date. Most are born within 2 weeks before or after. The due date is an estimate, not a deadline.
What if I conceived via IVF?
For IVF, use the conception date option and enter the embryo transfer date minus the embryo age (e.g., transfer date minus 5 days for a day-5 blastocyst).
When do the trimesters start?
First trimester: weeks 1-12. Second trimester: weeks 13-26. Third trimester: weeks 27-40. Each trimester brings different development milestones.
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