IVF method
Chinese Gender Calendar for IVF
IVF is the one case where the conception date is not an estimate; it is a date in your clinic notes. That makes it the most precise input this chart can take. Enter your transfer date and the embryo's age at transfer.
Dates from 1900-01-31 to 2101-01-28 are supported. Nothing you type leaves your browser The whole calculation runs on this page.
Why IVF dates are the cleanest input
Everyone else using this chart is working from an estimate. A due date was calculated from an assumed cycle; a last-period date is converted with an assumed ovulation day. Both can be off by a week or more, which near a lunar month boundary changes which column of the chart you land on.
With IVF, fertilisation happened on a known day in a lab. You do not have to guess. The only conversion needed is to count back from the transfer date by the embryo’s age:
- Day 3 transfer (cleavage stage): conception was 3 days before transfer.
- Day 5 transfer (blastocyst, the most common): 5 days before.
- Day 6 transfer (blastocyst): 6 days before.
Transfer date converted, by embryo day
For a transfer on 15 March 2026, here is what each embryo age works out to:
| Embryo at transfer | Conception date | Lunar month |
|---|---|---|
| Day 3 (cleavage stage) | 12 Mar | 1 |
| Day 5 (blastocyst) | 10 Mar | 1 |
| Day 6 (blastocyst) | 9 Mar | 1 |
In this example all three embryo ages land in the same lunar month, so the chart gives the same answer either way. That will not always be true; a transfer in the first few days of a lunar month can push a day-6 blastocyst back into the previous one.
Worked example
A mother born 15 June 1995, day-5 blastocyst transferred 15 March 2026:
- Count back 5 days → conception 10 March 2026.
- Lunar month of that date → 1.
- Her lunar age at conception → 32.
- Chart row 32, column 1 → Boy.
See row 32 for what that age predicts in every other lunar month.
Frozen transfers
With a frozen embryo transfer the embryo was created in an earlier cycle, sometimes years earlier, and then thawed. For this chart, count back from the transfer date by the embryo’s age at freezing, which is the date this pregnancy began, and it is what the calculator uses.
If you prefer to use the original fertilisation date from your notes, enter it directly with the conception date method. Both are defensible; the chart is folklore either way, so pick whichever feels more meaningful to you.
One thing worth saying plainly
IVF is often a long and difficult road, and it is easy for a fun chart to start feeling like a forecast when you are waiting. It is not one. The precision on this page is about reading the right cell of a traditional chart; it does not make the chart’s answer any more likely to be right than a coin toss. If you want to actually know, that is a conversation with your clinic.
IVF questions
Which date should I use for IVF, retrieval or transfer?
Use the transfer date and tell the calculator the embryo’s age at transfer. Fertilisation happened in the lab on the day of egg retrieval, so counting back from transfer by the embryo day gives you that exact date. For a day-5 blastocyst, conception was five days before transfer.
Does fresh versus frozen transfer change anything?
For the chart, what matters is the day the embryo was fertilised. With a fresh transfer that is simply the retrieval date. With a frozen transfer the embryo was fertilised in an earlier cycle, so counting back from the transfer date by the embryo day gives the date the embryo reached that stage, which is the date to use here, since it is the conception event this pregnancy came from.
Is the Chinese gender calendar more accurate for IVF?
The input is more precise, but the chart is not. Knowing the exact conception date removes one source of error, so you can be confident you are reading the right cell. The cell itself is still folklore with no predictive value.
We already know our embryo’s sex from PGT-A. Why use this?
If you have had preimplantation genetic testing you already know, with certainty, something this chart cannot tell you. Treat the calendar purely as a bit of fun at that point; nothing it says should carry any weight against a genetic result.