Enter IVF details
Use transfer dating for most embryo transfers. Use retrieval dating when you know the egg retrieval or ovulation date. Use LMP dating only when you want to enter an equivalent menstrual date directly.
Formula used
Estimated due date = Transfer date + (266 − embryo age in days)
Equivalent LMP = Transfer date − (embryo age + 14 days)
Estimated due date = Retrieval date + 266 days
Estimated due date = LMP date + 280 days
Why these formulas work:
- IVF pregnancies are usually dated from embryo development rather than a natural cycle guess.
- A 5-day transfer is already considered 2 weeks and 5 days pregnant on transfer day.
- The calculator converts that transfer timing into an equivalent menstrual timeline.
- Actual clinical dating may change after ultrasound review.
How to use this calculator
- Select the method that matches your available IVF date.
- Enter the transfer date, retrieval date, or equivalent LMP date.
- Choose embryo age if you are using transfer dating.
- Optionally set a beta test offset and an as-of date.
- Click the calculate button to see the due date and timeline.
- Review milestones, the gestational age, and the plotted pregnancy progress.
- Download the result as CSV or PDF for records and appointments.
Example data table
| Scenario | Reference date | Embryo age | Estimated due date | Equivalent LMP |
|---|---|---|---|---|
| Fresh transfer | January 15, 2026 | 5 days | October 3, 2026 | December 27, 2025 |
| Fresh transfer | March 10, 2026 | 3 days | November 28, 2026 | February 21, 2026 |
| Frozen transfer | April 2, 2026 | 5 days | December 19, 2026 | March 14, 2026 |
| Egg retrieval | February 5, 2026 | Not used | October 29, 2026 | January 22, 2026 |
Important note
This calculator supports planning and record keeping. It does not replace care from your fertility specialist or obstetric team. If your clinic gives a different date, follow the medical team’s advice.
FAQs
1) How accurate is an IVF due date calculator?
It is usually more precise than natural-cycle dating because embryo age and transfer timing are known. Clinics may still update the date after ultrasound findings or specific treatment details.
2) Why does embryo age matter?
A 3-day embryo and a 5-day embryo are not the same developmental age on transfer day. That difference changes the equivalent gestational age and shifts the estimated due date slightly.
3) Is the formula different for frozen transfers?
The main due date formula stays the same. Fresh and frozen transfers use the transfer date and embryo age. Frozen status mostly affects treatment history, not the calendar math.
4) Can I use egg retrieval instead of transfer date?
Yes. If you know the egg retrieval or ovulation date, the calculator can estimate the due date by adding 266 days. Transfer dating is often preferred when available.
5) What is an equivalent LMP date?
Equivalent LMP is a back-calculated menstrual date that matches IVF timing. It helps place the pregnancy on the standard 40-week obstetric timeline used in many prenatal records.
6) Should I follow this date or my ultrasound date?
Use this estimate for planning, but follow the date confirmed by your care team. Ultrasound and clinical review can refine timing when needed.
7) Why is there a beta test date option?
Some patients like a projected laboratory follow-up date after transfer. The offset is customizable because clinic testing schedules can vary.
8) Can this calculator predict labor day exactly?
No. A due date is an estimate, not a guarantee. Birth can happen before or after that date, even when IVF timing is known very well.