Free tool

IVF Due Date Calculator

IVF is the one pregnancy where the due date is not a guess. Because the day of fertilization is known, your due date is calculated, not estimated from a last period. Enter your transfer or retrieval date for your due date, how far along you are today, and your full timeline.

1. What date do you know?

Pick the event you have a date for. A frozen transfer (FET) dates the same as a fresh one of the same embryo age.

The most common transfer in modern IVF. A blastocyst is 5 days past fertilization. Fresh or frozen (FET) dates the same.

2. Your day 5 transfer date

Enter your date to see your due date

Because IVF dates conception precisely, your due date is more accurate than a typical estimate.

Method

How an IVF due date is calculated

Deterministic math, not a statistical guess. Every constant is a cited clinical standard.

The estimated due date is 280 days (40 weeks) from the last menstrual period, and gestational age is dated from that period, which falls about 14 days before ovulation. So from the day of conception a the estimated due date is 280 minus 14, or 266 days (ACOG, methods for estimating the due date).

In IVF, the day of fertilization is known: the egg retrieval is day 0, so an embryo transferred on day 5 is 5 days past fertilization. The estimated due date is therefore the transfer date plus (266 minus the embryo's age at transfer): a Day 5 blastocyst is plus 261 days, a Day 3 embryo is plus 263 days, a Day 6 blastocyst is plus 260 days, and counting from the egg retrieval date it is plus 266. A frozen transfer (FET) dates identically to a fresh transfer of the same embryo age.

The term classifications use ACOG definitions. Early term: 37 weeks through 38 weeks and 6 days. Full term: 39 weeks through 40 weeks and 6 days. Late term: 41 weeks through 41 weeks and 6 days. Post-term: 42 weeks and beyond. (ACOG Committee Opinion #579). These categories do not determine when an individual pregnancy should be delivered. Follow your clinician's pregnancy and delivery plan.

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FAQ

Common questions about IVF due dates

How is an IVF due date calculated?
Because IVF dates conception precisely, the due date is the known event plus (266 minus the embryo's age at transfer). A Day 5 blastocyst transfer is the transfer date plus 261 days, a Day 3 transfer is plus 263 days, and counting from the egg retrieval date it is plus 266 days. The 266 comes from a 280-day (40-week) pregnancy measured from the last period, minus the 14 days before ovulation.
Why is an IVF due date more accurate than a normal one?
A standard due date is estimated from the last menstrual period and assumes ovulation on day 14, which varies between people. In IVF the day of fertilization is known exactly (the egg retrieval), so the dating has no guesswork and is more precise than last-period dating.
Day 3 versus Day 5 transfer: does the due date differ?
Yes, by two days. For the same transfer date, a Day 3 embryo has a due date two days later than a Day 5 blastocyst, because the Day 3 embryo is two days younger and therefore two days further from term. This calculator handles each transfer day correctly.
Does a frozen embryo transfer (FET) change the due date?
No. The due date depends only on the embryo's age at transfer (Day 5, Day 6, and so on), not on whether the embryo was fresh or frozen. A frozen Day 5 blastocyst and a fresh Day 5 blastocyst transferred on the same date have the same due date.
How many weeks pregnant am I after embryo transfer?
Gestational age is counted from the last period, which is about 19 days before a Day 5 transfer, so on the day of a Day 5 blastocyst transfer you are already about 2 weeks and 5 days pregnant. Enter your date above to see exactly how far along you are today.
Will my baby be born on the due date?
A due date is an estimate, not a prediction of the day of birth. Early term: 37 weeks through 38 weeks and 6 days. Full term: 39 weeks through 40 weeks and 6 days. Late term: 41 weeks through 41 weeks and 6 days. Post-term: 42 weeks and beyond. These categories do not determine the right delivery date for an individual pregnancy. Follow your clinician's pregnancy and delivery plan.

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IVFcost.co is an informational data platform, not a clinic or medical provider. This calculator is an evidence-based estimate, not medical advice. Your clinic's dating ultrasound is the number to follow, and any concern about your pregnancy should go to your clinician.