Pregnancy
IVF Due Date Calculator
PanaKit's IVF due date calculator estimates your due date from your embryo transfer date and whether you had a day 3 or day 5 embryo transfer. It works the same for fresh IVF and frozen embryo transfer (FET), since dating uses the embryo's age at transfer, not storage time. Runs instantly in your browser, and nothing you enter is stored or sent anywhere.
Estimate Your IVF or FET Due Date
Fresh or frozen transfer: the math is the same either way. Dating uses the embryo's age at transfer, not how long it was stored frozen.
Your dates stay on this device. Offsets match standard day 3 and day 5 IVF/FET dating (261 / 263 days).
Enter your transfer date and embryo stage to see your estimate.
How it's calculated
Day 5 (blastocyst): due date = transfer date + 261 days. Example: transfer on March 1 → due date November 17. Day 3 (cleavage stage): due date = transfer date + 263 days. Example: transfer on March 1 → due date November 19. Frozen embryo transfer (FET) uses the exact same math as a fresh transfer, based on the embryo's age at transfer, not how long it was stored frozen. Storage time does not change the calculation. Day 6 blastocyst transfers are less standardized across clinics than day 3 or day 5. Some clinics date day 6 transfers the same as day 5 (+261 days), but practice varies. If you had a day 6 transfer, confirm which convention your clinic uses, or use the day 5 estimate as a starting point only. Equivalent LMP for handoff to standard OB dating: for day 5, transfer date − 19 days; for day 3, transfer date − 17 days. That is the LMP date your OB's calendar would use if switching from IVF dating to standard LMP dating.
Frequently asked questions
None, mathematically. Both use the embryo's age at transfer, day 3 or day 5, to calculate the due date. How long an embryo was frozen before transfer doesn't change the calculation at all. For how FET due dates are calculated step by step, see how to calculate your FET due date.
Add 261 days to your transfer date. This accounts for the embryo already being 5 days old at transfer, compared to counting from a theoretical last menstrual period.
Add 263 days to your transfer date. The embryo is 2 days younger at transfer than a day 5 blastocyst, so 2 extra days are added to reach the same effective conception based timeline.
Practice varies by clinic. Some date day 6 transfers the same as day 5 (plus 261 days), while others use a slightly different offset. If you had a day 6 transfer, confirm which convention your clinic uses rather than assuming either figure applies exactly.
They're calculated differently but should land on a similar due date for the same actual conception timing. IVF dating works from your exact transfer date, which is more precise than LMP based dating, since LMP assumes ovulation happened around day 14 of an average cycle rather than using a known, exact date.
In gestational age terms you're 2 weeks 5 days pregnant on the day of a day 5 transfer, and 2 weeks 3 days on the day of a day 3 transfer, because gestational age counts from the equivalent LMP (19 or 17 days before transfer).
It should be very close, since clinics use the same transfer date and embryo age based formulas. Small differences can occur if your clinic made a manual adjustment based on additional factors specific to your case, if so, your clinic's number is the one to go with.
Sometimes. Transfer-based dating is usually very precise, but a first-trimester growth scan can still lead your clinic to refine the official due date if measurements differ meaningfully. When in doubt, use your clinic's date.