Pregnancy Due Date Calculator
Find out when your baby is likely to arrive. Choose your method — last period, conception date, or IVF embryo transfer — and see your estimated due date, current week, and trimester.
Pregnancy Due Date Calculator
Find out when your baby is likely to arrive. Choose your method — last period, conception date, or IVF embryo transfer — and see your estimated due date, current week, and trimester.
Informational only — not medical advice or a diagnosis. Every pregnancy and cycle is different, and these results are estimates. Always consult your OB-GYN or midwife.
Enter your dates above to see your result.
This is an educational estimate, not medical advice. Consult a qualified professional. For pregnancy and cycle decisions, follow your OB-GYN — guidance reflects the American College of Obstetricians and Gynecologists (ACOG).
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How your due date is calculated
The classic method is Naegele’s rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). It assumes a regular 28-day cycle with ovulation on day 14, which is why a due date is an estimate rather than a fixed appointment.
If you know your conception date, the calculator adds 266 days (38 weeks) instead, since pregnancy is dated from about two weeks before conception. For IVF, it uses your transfer date and the embryo’s age — a day-5 (blastocyst) transfer counts as 19 days of gestation already, a day-3 transfer as 17 — giving a more precise date than LMP alone.
Weeks and trimesters
Pregnancy is measured in gestational weeks counted from your LMP, and divided into three trimesters: the first runs to the end of week 13, the second from weeks 14–27, and the third from week 28 to birth. This tool shows where you are today alongside your due date.
An ultrasound in the first trimester is the most accurate way to date a pregnancy and may adjust your due date. If your dating scan differs from your LMP estimate by more than about a week, your care team will usually use the scan date.
Why the date is only an estimate
Only about 1 in 20 babies are born on their exact due date. A full-term birth can happen any time between 37 and 42 weeks, and factors such as cycle length, irregular ovulation and individual variation all affect timing.
Use your due date to plan and to track milestones, but hold it loosely. Your OB-GYN or midwife will monitor your pregnancy and let you know if anything about your dating or timing needs attention.
Frequently asked questions
How accurate is a due date calculator?
It gives a solid estimate, but only about 5% of babies arrive on the exact date. A first-trimester ultrasound is the most accurate way to confirm or adjust your due date.
What is Naegele’s rule?
Naegele’s rule estimates your due date by adding 280 days (40 weeks) to the first day of your last menstrual period, assuming a regular 28-day cycle.
How is an IVF due date different?
IVF dating uses the known transfer date and embryo age, so it is often more precise than LMP. A day-5 transfer already counts as 19 days of gestation.
Sources & references
Not medical advice. This result is an educational estimate from HealthyLifeStyles (Trusted Wellness), based on population formulas — not a diagnosis or treatment. Always consult a qualified healthcare professional about your health.
https://www.healthylifestyles.com/tools/due-date-calculator