IVF due date calculator
In IVF the embryo age is known exactly, so the due date comes from the transfer day and embryo age instead of the last period.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter transfer or retrieval date and date type.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Due date = transfer date + (266 - embryo age in days). Day 3 transfer: + 263 days, day 5: + 261, day 6: + 260. From the egg retrieval date: + 266 days.
Example
Inputs: Transfer or retrieval date = 2026-02-01, Date type = Day 5 embryo transfer (blastocyst). Result: Estimated due date: Tuesday, October 20, 2026 (2026-10-20); Equivalent last period date: Tuesday, January 13, 2026 (2026-01-13); Pregnancy age on that day: 2 weeks 5 days.
Limits and caveats
- It assumes an average pregnancy length; twins usually arrive earlier.
- For a frozen transfer, use the embryo’s age when it was frozen.
Questions about this tool
Why is the pregnancy two weeks and some days old on transfer day?
Pregnancy age is counted as if the last period were 14 days before fertilization, and the embryo age is added on top.
Is a frozen transfer calculated differently?
The same way: use the transfer date and the embryo’s age when frozen, so a day 5 embryo adds 261 days.
Will my clinic give a different date?
It may adjust slightly after an early scan, but usually by only a day or two.