Chinese Calendar Baby Gender 2025: Checking a 2025 Conception

The chart reads two things: the mother's lunar age at conception, and the lunar month in which conception happened. The lunar month is where 2025 is unusual. Here is every month of the 2025 lunar year, taken from the Hong Kong Observatory Gregorian-Lunar conversion tables for 2025 and 2026, read on October 15, 2026.

Source: Hong Kong Observatory conversion tables T2025e and T2026e, read October 15, 2026. The 2025 lunar year has 13 months and 384 days.

Two practical points follow from the table. First, the lunar year 2025 did not end on December 31: it ran until February 16, 2026, so a conception in January or early February 2026 is a 2025 conception as far as the chart is concerned. Second, the lunar months after the leap month start roughly a month later than many people expect. A conception on September 1, 2025 is in lunar month 7, not month 8.

The Chinese calendar keeps pace with the seasons by adding a thirteenth month roughly once every three years. In 2025 that extra month was a second sixth month. The gender chart only has twelve columns, so a leap month has to be read as one of them. The common convention, and the one our calculator follows, is to treat it as the month it repeats: the leap sixth month is read as month 6. We explain the general rule in our guide to how many months are in the Chinese lunar year.

A tool that skips the leap month does something worse than misreading one month. It shifts every month after July 24 by one column. We wanted to know how much that matters in practice, so we counted it on our own chart. For each pair of neighbouring months, we checked all 28 lunar-age rows (18 to 45) and counted the rows where the two columns disagree.

Counted from the chart in this site's calculator, October 2026.

So for a conception between late July 2025 and mid-January 2026, a tool that ignores the leap month gives the opposite answer almost half the time. If you remember getting “boy” from one website and “girl” from another for the same 2025 dates, this is the most likely reason. Our article on why Chinese gender calculators give different results covers the other causes.

If the arithmetic for lunar age feels slippery, our lunar age calculator shows each step, and the guide to the lunar age of the mother explains the rule with six more real birth dates.

The row of the chart is the mother's lunar age, and for a 2025 conception it depends only on her lunar birth year: lunar age = 2025 − lunar birth year + 1. Your lunar birth year is your Western birth year, unless you were born before that year's Chinese New Year, in which case it is the year before. Remember that a conception from February 17, 2026 onward is lunar 2026, so add one to everything below for those.

Chinese New Year dates from the Hong Kong Observatory tables for each birth year. Born before the date in the third column? Your lunar age is one higher.

Notice what is not in that rule: your birthday. Lunar age changes for everyone at once, at Chinese New Year, so two women born in the same lunar year have the same lunar age for the whole of 2025, whatever month their birthdays fall in. The most common mistake we see is taking a Western age and adding one, which is wrong for part of every year. Until October 2026 our own calculator used a shortcut of that kind and got the lunar age wrong for many mothers; it now counts Chinese New Years exactly as the table above does.

Most people who land here already know the answer that matters: whether they had a boy or a girl. Comparing that with the chart is a nice ritual, and it is how the chart has survived for generations. Families remember when it was right and forget when it was wrong.

It is worth knowing how that comparison has gone at scale. Researchers applied the chart to 2,840,755 births in Sweden between 1973 and 2006, computing each mother's lunar age and lunar month of conception, and found its predictions agreed with the baby's sex no better than chance (Villamor et al., 2010). They even re-ran it with a website's own lunar conversion and with no lunar conversion at all; nothing changed. A baby's sex is set at fertilization by whether the sperm carries an X or a Y chromosome, as MedlinePlus Genetics explains, and the calendar has no way to see that.

So if the chart matched your 2025 baby, enjoy the story. If it did not, you are in very good company, roughly half of everyone who has ever tried it. Our deeper look at what the scientific evidence says walks through the Swedish study in detail.

If you found this page while planning a pregnancy, the year you want is not 2025. The lunar year 2026, the Year of the Horse, runs from February 17, 2026 to February 5, 2027, and the 2026 chart page lists its months. For conceptions next year, see the 2027 chart page and our guide to planning across 2026 and 2027. Or go straight to the Chinese gender calendar calculator, which now handles every lunar month from January 29, 2025 to February 2, 2030.