Due date calculator (EDD)
Estimate EDD from LMP, conception/IVF, or ultrasound. Adjust cycle length and compare methods. Informational estimate only.
Calculation result
Estimated date
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Likely window
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from the calculated date.
Typical window (37+0 to 41+6)
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How it was calculated
The summary will appear once you complete the form.
Milestone guidance
Approximate timings for common checks.
Week-by-week calendar
Estimated date ranges from week 30 onward.
| Week | Estimated dates |
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Important notice
For guidance only. Always confirm with your healthcare professional. No personal data is stored.
Frequently asked questions
How do I calculate the estimated due date from my LMP?
Add 280 days to the first day of your last menstrual period. If your cycle length differs from 28 days, adjust it in the calculator and choose Naegele’s rule or the Parikh method to reflect your pattern.
How do I calculate the EDD from an ultrasound?
Enter the ultrasound date plus the gestational weeks and days stated in the report. The tool projects that gestational age onto your real-life calendar to generate an updated EDD.
How can I find my due date if I know the conception day?
When the exact day of ovulation or insemination is known, add 266 days to obtain the due date. That same logic applies to timed intercourse, IUI and other assisted conception procedures.
How is the due date calculated for IVF pregnancies?
Select the IVF protocol you followed. The calculator adds 266 days after egg retrieval, 263 days after a day-3 transfer and 261 days after a day-5 transfer to reflect embryonic development.
When will my baby be born based on my weeks of pregnancy?
Most babies arrive between 37 and 42 weeks. The dashboard shows how many days remain, highlights the typical window and links to a milestone timeline you can share with your provider.
Is the estimated due date exact?
No. Only about 5% of births happen on the predicted date. Use the EDD as a guide and discuss any concerns with your midwife or obstetrician; early ultrasounds usually provide the tightest margin of error.
The estimated due date (EDD) is a medical projection that signals when a baby is most likely to arrive. Our calculator combines the leading approaches: LMP-based dating with Naegele’s rule or the Parikh adjustment for irregular cycles, conception or IVF timelines, and early ultrasound measurements. Enter your information to receive an updated EDD, the precise gestational age, a custom variation range, and the typical pregnancy window (−21 to +13 days) used by maternity teams. You can also compare outcomes when you know the exact ovulation day, conceived via assisted reproduction, or had your due date revised after an ultrasound. Everything runs in your browser and feeds an editable timeline so you can review the schedule before your next appointment. Remember every pregnancy is unique, and first-trimester scans usually deliver the narrowest margin of error.
Calculate due date by LMP (Naegele / Parikh method)
To perform the LMP due-date calculation, the tool applies Naegele’s rule (LMP + 280 days) as the baseline and lets you enable the Parikh method whenever your cycle length differs from 28 days. Just enter the first day of your last period, adjust the average cycle length, and the system will adapt the due date with a buffer tailored to your pattern.
Calculate due date by conception or IVF
If you want to estimate the due date from conception, pick the corresponding mode and provide the exact day of ovulation, insemination or embryo transfer. The IVF calculator supports three scenarios: egg retrieval (266 days), day-3 transfer (263 days) and day-5 transfer (261 days), giving you an EDD aligned with each protocol.
Calculate due date by ultrasound
To project the EDD from an ultrasound, enter the exam date plus the weeks and days listed in the report. The calculator maps that gestational age onto today’s calendar and lets you specify a reference appointment date to keep track of how the ultrasound-based due date evolves.
When will my baby be born?
Once you submit the form, the results panel shows how many days remain until delivery, summarises when you might “hit your due date”, and links to the personalised timeline. It helps you answer the classic “when will I give birth?” question with data and share the overview with your care team.
Typical window and pregnancy variability
The typical pregnancy window spans from 37+0 to 41+6 weeks, equivalent to −21 and +13 days around the EDD. You can customise this range in Advanced options to reflect twin pregnancies, obstetric history or clinical advice, understanding that the due date represents a moving window rather than a single fixed day.
