Calculate how many weeks pregnant you are online free - no login. Enter the first day of your last period or conception date to find your current pregnancy week and estimated due date.
Knowing your exact week matters for scheduling scans, understanding what's developing, and communicating clearly with healthcare providers who use the same obstetric dating system. This calculator gives you the same number your OB would calculate from your LMP.
Enter your last menstrual period (LMP) date and instantly get your estimated due date, how many weeks pregnant you are right now, and which trimester you're in. Uses the standard Naegele's rule: LMP + 280 days.
Calculate due date after a positive pregnancy test, find out how many weeks pregnant you are right now, determine which trimester you are currently in, plan for anatomy scan and prenatal appointments, count weeks since conception for tracking, and share an accurate due date with family.
The most common question is how accurate the due date is. Only about 5% of babies are born exactly on their due date - the typical delivery window is between 37 and 42 weeks. The due date is a target, not a guarantee.
Input the first day of your last menstrual period.
The tool calculates your gestational age and due date.
View your current week, trimester, and days remaining.
See your estimated due date (EDD) clearly displayed.
Common questions about this tool and how to use it.
The standard method is Naegele's Rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). This assumes a 28-day cycle with ovulation on day 14. For example, if your LMP was January 1, your due date would be October 7. Your OB may adjust this date based on ultrasound measurements, particularly in the first trimester.
Pregnancy week is counted from the first day of your last menstrual period (LMP), not from conception. Conception typically occurs around week 2. So at the time a positive pregnancy test appears (around week 4), you are already considered 4 weeks pregnant. Enter your LMP date in this calculator to see your exact current week.
First trimester: weeks 1–13. Second trimester: weeks 14–27. Third trimester: weeks 28–40. Key milestones: fetal heartbeat is usually detectable by week 6–7. The anatomy scan (morphology scan) is done around weeks 18–20. The baby is considered full-term at week 37.
Only about 5% of babies are born on their exact due date. Most births occur within 2 weeks before or after - roughly 80% of births happen between weeks 38 and 42. The due date is a statistical estimate, not a precise prediction. First ultrasound measurements (crown-rump length) in the first trimester provide the most accurate dating when available.
Yes - but the calculation is different. For IVF with fresh embryo transfer, add 266 days (38 weeks) to the egg retrieval date. For a 3-day embryo transfer, add 263 days. For a 5-day blastocyst transfer, add 261 days. Your fertility clinic will provide the expected due date, but these formulas give a reliable estimate.
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