IVF Due Date Calculator
Calculate your estimated due date based on your specific IVF procedure.
Estimated Due Date:
How IVF Due Dates are Calculated
Unlike natural conception, where doctors calculate the due date based on the first day of your last menstrual period (LMP), IVF provides a much more precise biological starting point. Because the exact moment of fertilization or embryo transfer is known, the calculation is highly accurate.
Calculation Methods by Transfer Type
A full-term pregnancy is traditionally calculated as 266 days from conception (or 280 days from LMP). In IVF, we adjust this based on the age of the embryo at the time of transfer:
- 5-Day Transfer (Blastocyst): Since the embryo is already 5 days old, your due date is 261 days (266 – 5) from the transfer date.
- 3-Day Transfer: Since the embryo is 3 days old, your due date is 263 days (266 – 3) from the transfer date.
- Egg Retrieval: If you are calculating from retrieval, the due date is exactly 266 days after the retrieval date, which is considered the date of fertilization.
Why the "Last Period" Method is Less Accurate for IVF
Many pregnancy apps use the First Day of Last Menstrual Period (LMP). However, in IVF cycles—especially medicated frozen embryo transfers (FET)—your "period" is often controlled by hormones. Using the procedure date eliminates the guesswork involved in ovulation timing, providing a more reliable timeline for prenatal care and milestone tracking.
Example Calculation
If you had a 5-day embryo transfer on October 1st:
- Standard gestation: 266 days
- Embryo age adjustment: -5 days
- Calculation: October 1st + 261 days = June 19th of the following year.