Pregnancy Due Date Calculator
Calculate your estimated due date, current pregnancy week, trimester, and important milestones.
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Important Disclaimer
This calculator provides estimates for educational purposes only. Results are not a substitute for professional medical or nutritional advice. Always consult a qualified healthcare provider before making significant changes to your diet or exercise routine.
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Frequently Asked Questions About Pregnancy Due Dates
How is my due date calculated?+
Doctors use Naegele’s rule: add 280 days (40 weeks) to the first day of your last menstrual period. If you know your conception date, add 266 days instead. Your due date may later be adjusted based on an early ultrasound.
How accurate is a pregnancy due date calculator?+
Only about 4–5% of babies arrive exactly on their due date. Most are born within two weeks either side of it. An early ultrasound (before 14 weeks) is the most accurate way to date a pregnancy.
How many weeks pregnant am I?+
Pregnancy is counted from the first day of your last period, not from conception — so at conception you are already about 2 weeks pregnant. Enter your last period date above to see your current week and trimester.
When does each trimester start?+
The first trimester runs from week 1 to the end of week 13, the second from week 14 to the end of week 27, and the third from week 28 until birth, usually around week 40.