Conception Calculator
Calculate Your IVF Due Date From Embryo Transfer Date
Enter the transfer date and select a day 3, day 5, or day 6 embryo to estimate your pregnancy timeline.
Dates are estimates for general information. They are not a diagnosis and do not replace dating by your prenatal or fertility care team.
How an IVF Due Date Calculator Uses Embryo Transfer Date
IVF dating starts with two documented details: the embryo transfer date and the embryo's age on that date. The general formula is estimated due date equals transfer date plus 266 days minus embryo age. Subtracting embryo age moves the timeline back to estimated fertilization before adding the standard 38 weeks from conception.
ACOG recommends assigning the estimated due date for an assisted-reproduction pregnancy from the embryo age and transfer date. Enter the date and embryo age recorded by your fertility clinic. A planned transfer can produce a future planning estimate, but it does not indicate that implantation or pregnancy will occur.
IVF Due Date for Day 3, Day 5 and Day 6 Embryo Transfers
For a day-3 cleavage-stage embryo, the calculator adds 263 days to the transfer date. For a day-5 blastocyst, it adds 261 days. For a day-6 embryo, it adds 260 days. The one-day difference between day 5 and day 6 reflects the additional day of embryo development before transfer.
Select embryo age rather than the number of days since egg retrieval unless your clinic has confirmed they are the same for the treatment cycle. If the embryo underwent an unusual culture, thaw, or transfer protocol and you are unsure which age applies, use the due date supplied by the clinic instead of guessing.
Fresh vs Frozen Embryo Transfer Due Date Calculation
Fresh and frozen embryo transfer dates use the same due-date formula when the transfer date and embryo age are known. The calculation does not add or remove days merely because an embryo was frozen. What matters for this calendar is how old the embryo was when it was transferred.
A frozen embryo transfer is often abbreviated FET. Whether the cycle was natural, medicated, donor-egg, or involved a previously frozen embryo does not change the two fields this calculator uses. Clinical protocols can be more complex, so keep the clinic's documented dating as the authoritative record.
How Many Weeks Pregnant Are You on IVF Transfer Day?
Gestational age still uses an equivalent LMP date, even though treatment provides a known laboratory timeline. On a day-3 transfer date, gestational age is 2 weeks 3 days. On a day-5 transfer date it is 2 weeks 5 days, and on a day-6 transfer date it is 2 weeks 6 days.
This convention can feel surprising because the transfer has just occurred, but it keeps IVF pregnancy weeks comparable with standard obstetric dating. The equivalent LMP shown in the result is a calculated reference date, not a claim that a menstrual period actually began on that date during treatment.
How to Read Your IVF Pregnancy Milestones and Delivery Window
The result includes estimated fertilization, equivalent LMP, gestational age today, trimester reference points, week 37, the 40-week due date, and a broad 37-to-42-week delivery window. These dates help organize a calendar but do not predict implantation, viability, scan findings, or delivery timing.
Use the timeline for general planning and compare it with your clinic portal or written instructions. Contact the fertility or prenatal care team when an embryo age, transfer date, ultrasound date, or due date appears inconsistent. Their treatment records take priority over this calculator.
Sources for This IVF Due Date Calculator Method
Our formulas and interpretation notes were reviewed against the following clinical and public-health references on August 2, 2026. These sources explain general dating methods and do not validate an individual result.
Frequently Asked Questions About IVF Due Date Calculations
How many days do I add after a day-5 embryo transfer?
Add 261 days to a day-5 embryo transfer date to estimate the due date. The result is equivalent to 266 days from estimated fertilization.
How do I calculate a due date after a day-3 embryo transfer?
Add 263 days to the day-3 transfer date. The shorter embryo age means two more days are added than for a day-5 transfer.
Is the IVF due date formula different for a frozen embryo transfer?
No. Fresh and frozen transfers use the same formula when embryo age and transfer date are known. Select the embryo age documented by your clinic.
What is the equivalent LMP date after an IVF transfer?
It is 14 days before estimated fertilization. On transfer day, subtract 17 days for a day-3 embryo, 19 days for day 5, or 20 days for day 6.
Should I use the IVF calculator instead of my clinic due date?
No. Use the due date documented by your fertility or prenatal care team. This calculator is for general date estimation and planning only.