IVF Due Date Calculator

How an IVF Due Date Is Different

A regular pregnancy due date is usually estimated from the first day of your last menstrual period, which means the actual date of conception is a guess. With IVF, the fertilization date is known precisely — it's your egg retrieval day — which makes the due date estimate more reliable than a standard last-period-based calculation.

From there, your due date is calculated the same way any pregnancy is: roughly 266 days (38 weeks) after fertilization, which lines up with the traditional 40 weeks counted from the last menstrual period.

How to Use This Calculator

Enter the date your embryo was transferred and select whether it was a Day 3 (cleavage stage) or Day 5 (blastocyst) transfer — you'll find this on your clinic's paperwork. The calculator works backward to your estimated egg retrieval date, then forward to your due date and a few key milestones along the way.

How We Calculate It

The estimated retrieval date is your transfer date minus 3 or 5 days, depending on the embryo stage you select. Your due date is then set at 266 days after that retrieval date. This matches the convention most fertility clinics use, though some may calculate slightly differently — your clinic's estimate, based on your specific cycle, always takes priority over this tool.

The milestone dates (end of first trimester, start of third trimester, and full term) are calculated the same way regular pregnancy weeks are counted, using your estimated retrieval date as the reference point for conception.

A Few Notes

Only about 1 in 20 babies actually arrive on their exact due date — full-term delivery normally happens anywhere between 37 and 42 weeks. This calculator gives you a planning estimate, not a medical prediction, and it isn't a substitute for the dating and monitoring your fertility clinic or OB provider will do throughout your pregnancy.