Calculate your estimated due date after IVF embryo transfer. Supports Day-3 and Day-5 blastocyst transfers with precise dating.
IVF pregnancies have a unique advantage when it comes to due-date accuracy: the exact age of the embryo is known. Whether you had a Day-3 cleavage-stage transfer or a Day-5 blastocyst transfer, this calculator uses the precise embryo age and transfer date to determine your estimated due date.
For a Day-3 transfer, the calculator adds 263 days to the transfer date, because the embryo is already 3 days past fertilization (266 − 3 = 263). For a Day-5 blastocyst transfer, it adds 261 days (266 − 5 = 261). This method is considered the most accurate way to date an IVF pregnancy.
This calculator works for both fresh and frozen embryo transfers (FET). The key date is the day of transfer, not the day of egg retrieval or fertilization. If you had assisted hatching or other procedures, the transfer date remains the reference point. Whether you are a beginner or experienced professional, this free online tool provides instant, reliable results without manual computation.
IVF due dates are more precise than LMP-based estimates because the embryo's exact age is known to the day. Using this calculator ensures your prenatal care milestones, screening windows, and delivery planning are based on the most accurate dating possible. It also helps you track gestational age correctly from the very start.
Day-3 Transfer: EDD = Transfer Date + 263 days Day-5 Transfer: EDD = Transfer Date + 261 days General: EDD = Transfer Date + (266 − embryo_age_days) LMP Equivalent = Transfer Date − embryo_age_days − 14 days
Result: October 8, 2026
With a Day-5 blastocyst transfer on January 20, 2026, the EDD is January 20 + 261 = October 8, 2026. The LMP equivalent is January 1, 2026 (transfer date minus 5 days minus 14 days). Gestational age at transfer is 2 weeks and 5 days.
The standard gestation from fertilization to birth is 266 days. Since an IVF embryo's age is precisely known, we subtract the embryo age from 266 and add the result to the transfer date. For Day-5 blastocysts: 266 − 5 = 261 days. For Day-3 embryos: 266 − 3 = 263 days.
The calculation is identical for fresh and frozen embryo transfers. A Day-5 blastocyst that was frozen and thawed is still a Day-5 embryo on the day of transfer. The only date that matters is the day the embryo entered the uterus.
Reproductive endocrinologists consider IVF-derived due dates to be the most accurate available. The embryo's age is documented to the hour, and the transfer date is recorded precisely. Even early ultrasound measurements have a margin of error of 3-5 days, while IVF dating is accurate to within 1-2 days.
In IVF, the exact day of fertilization and embryo transfer is documented by the clinic. This eliminates the guesswork about ovulation timing that affects LMP-based dating. The precision can be as close as 1-2 days.
A Day-3 embryo is at the cleavage stage (6-8 cells), while a Day-5 embryo is a blastocyst (100+ cells). Day-5 transfers allow more time to identify the healthiest embryos and have higher implantation rates. The due date differs by 2 days between the two.
No. Whether the embryo was fresh or frozen, the due date calculation is the same. The embryo's age at transfer (Day 3 or Day 5) is what determines the due date, not whether it was previously frozen.
The LMP equivalent is a calculated date that represents what your last menstrual period would have been if you conceived naturally. It is used for medical records and gestational age tracking. For Day-5: LMP = Transfer Date − 19 days.
For IVF pregnancies, most providers will keep the IVF-calculated date unless the ultrasound differs by more than 5-7 days, which is uncommon. IVF dating is typically more reliable than ultrasound dating.
Yes, the calculation is the same regardless of whether you used your own eggs or donor eggs/embryos. The transfer date and embryo age at transfer are the only factors needed.
At a Day-5 transfer, gestational age is 2 weeks and 5 days (14 + 5 = 19 days). At a Day-3 transfer, it is 2 weeks and 3 days. This accounts for the 14 days of the LMP-equivalent pre-ovulation period.
An IVF pregnancy is the same 40 weeks as a natural pregnancy, measured from the LMP equivalent. Full term is 39-40 weeks, with most IVF pregnancies delivering in the typical 37-42 week range.