IVF Due Date Calculator

An IVF pregnancy is dated from the day of fertilization, which is embryo day 0, plus 266 days. For an embryo transfer the embryo is already a few days old, so a day 3 transfer adds 263 days, a day 5 adds 261, and a day 6 adds 260. For an egg retrieval the tool adds the full 266 days because fertilization happens that same day.

With IVF the exact day of fertilization is known from your transfer or retrieval date, so there is no guesswork about when you ovulated. Standard Naegele dating assumes a 28-day cycle and ovulation 14 days after your last period, which can be off by several days if your cycle is shorter or longer.

Gestational age is measured from a virtual last menstrual period placed 14 days before fertilization, which is the standard obstetric convention. By that scale you are already about 2 to 3 weeks along on your transfer day. The tool reports your current weeks and days plus your trimester.

No. For dating, only the embryo's age at transfer matters, not whether it was fresh or frozen. A day 5 blastocyst is dated the same way whether it is a fresh transfer or an FET, so just pick the embryo day (3, 5, or 6) that matches your transfer.

The estimated due date is a midpoint, not a deadline. Only about 1 in 20 babies arrive on the exact date. Current obstetric terminology splits term birth into early term from 37w0d to 38w6d, full term from 39w0d to 40w6d, late term from 41w0d to 41w6d, and postterm from 42w0d. Your clinic may adjust the date after an early ultrasound.

No. It is for general education and planning only and is not a substitute for professional medical advice, diagnosis, or treatment. Your fertility clinic's due date, based on ultrasound dating, takes precedence, so always follow your care team's guidance.