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IVF Due Date Calculator

If you conceived through IVF, your due date is easier to pin down than most — the fertilization day is known, so there’s no guessing about ovulation. Enter your embryo transfer date (Day-5 blastocyst or Day-3 cleavage) or your egg retrieval date, and this calculator gives your estimated due date plus how many weeks pregnant you are today. It uses the same 40-week framework your clinic does, adjusted for the age of the embryo at transfer, so the number lines up with what your fertility team will tell you.

Calculate from

The day your blastocyst embryo was transferred.

Pick your transfer or retrieval date to see your estimated due date.

How the IVF Due Date Calculator works

A standard due date estimate adds 280 days to the first day of your last period and assumes you ovulated on day 14. IVF removes that assumption. Because the egg and sperm meet in the lab on a known day, we can count forward from fertilization instead of a guessed cycle.

The baseline is fertilization date + 266 days = due date. Egg retrieval is the fertilization day, so a retrieval date gets the full 266 days. For a transfer, the embryo has already been growing for a few days, so we subtract its age:

  • Day-5 (blastocyst) transfer: transfer date + 261 days
  • Day-3 (cleavage) transfer: transfer date + 263 days
  • Egg retrieval: retrieval date + 266 days

Gestational age is still counted from a notional last period, two weeks before fertilization. That is why you’re already “2 weeks pregnant” on retrieval day — it’s a convention every pregnancy app and clinic shares, not a quirk of this tool.

Why IVF dating is more precise

With a natural conception, the due date hinges on two unknowns: the exact day you ovulated and how long your cycle runs. Both can swing the estimate by a week in either direction. IVF replaces those unknowns with a calendar entry from the lab, so the starting point is exact.

Precise math still isn’t the final word. Babies arrive across a normal range of roughly 37 to 42 weeks, and your clinic’s first ultrasound — usually around 6 to 8 weeks — confirms dating from the embryo’s measured size. If the scan date and the calculator date differ by a few days, your care team’s scan wins. Treat this tool as a friendly planning estimate while you wait for that appointment.

When to check in with your clinic

This calculator is for planning and reassurance, not monitoring. Reach out to your fertility clinic or healthcare provider — don’t wait for a scheduled appointment — if you have:

  • Heavy bleeding, severe cramping, or sharp one-sided pain
  • Dizziness, fainting, or shoulder-tip pain (possible signs needing urgent review)
  • A positive then suddenly negative pregnancy test
  • Any symptom that worries you, however small it seems

Your IVF team scheduled your beta-hCG blood tests and early scans for a reason — those, not a due-date estimate, are how a pregnancy is confirmed and followed.

Frequently asked questions

How is an IVF due date calculated?
IVF dating works backward from the known fertilization day rather than a guessed last period. From egg retrieval we add 266 days. From a Day-5 blastocyst transfer we add 261 days (266 minus the embryo's 5 days of age), and from a Day-3 transfer we add 263 days. Because the conception date is known to the day, an IVF due date is usually more precise than a standard last-period estimate.
What is the difference between a Day-3 and Day-5 transfer due date?
The embryo is two days older at a Day-5 (blastocyst) transfer than at a Day-3 (cleavage) transfer, so from the same calendar date a Day-5 transfer gives a due date two days earlier. The calculator handles this for you — just pick the transfer type that matches your cycle and the math adjusts automatically.
How many weeks pregnant am I after embryo transfer?
Pregnancy is counted from a notional last period, which is two weeks before fertilization. So on egg retrieval day you are considered 2 weeks pregnant, on a Day-3 transfer day about 2 weeks 3 days, and on a Day-5 transfer day about 2 weeks 5 days. The calculator shows your current gestational age in weeks and days based on today's date.
Is an IVF due date more accurate than a normal due date?
It is usually more precise on paper because the fertilization date is known exactly, removing the guesswork of cycle length and ovulation timing. That said, every estimate is a starting point. Your fertility clinic's early ultrasound dating is the figure your care team will use, and it takes priority over any calculator.
Does this calculator store my dates?
No. Everything runs in your browser. Your transfer or retrieval date is never sent to a server, saved to a database, or shared. Refreshing the page clears your inputs.

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— The Period Tools Team