Chinese Gender Predictor – Boy or Girl by the Traditional Chart

The grid printed on this page is the traditional Chinese gender chart — the lunar chart that tradition says was drawn up in imperial China, that legend says spent centuries buried in a royal tomb outside Beijing, and that families have copied, reprinted and passed around ever since. Every label on this page uses those words deliberately: this is the traditional chart, presented as a piece of cultural tradition, and the result it gives is always phrased the same way — the traditional chart is said to read boy or girl for this cell. That attributed framing is not a stylistic quirk. It is the honest description of what the object is: a folk table whose claims belong to the tradition that carries it, not to medicine and not to this page.

So, to be explicit about what the chart is and is not. It is a genuine traditional artefact: a fixed grid of 336 cells in which the mother’s age, reckoned the traditional Chinese way in lunar years, is crossed with the lunar month of conception. It is not a diagnostic test, a screening tool or a source of medical information, and nothing on this page should be read as a finding about any real pregnancy. The tradition itself makes a claim — that the cell foretells a boy or a girl — and this page reports that claim in the tradition’s own terms, the way a museum label reports what an object was believed to do. Where the claim has been tested against real birth records, it has scored about 50 percent, and the evidence section below says so in full.

One more boundary, stated plainly: this page offers no gender-selection advice. The chart is sometimes described in folklore as a planning aid, but a table that is right as often as a coin cannot steer an outcome, and this page will not pretend otherwise. Use the calculator the way the tradition is best enjoyed — as a cultural curiosity and a party game, with the answer held lightly until a scan or a blood test, arranged through a doctor or midwife, provides a real one.

The calculator does nothing the paper chart does not: it finds one cell. To read the grid by hand, start with the mother’s lunar age — worked out in the lunar-age section below, or converted for you by the two date fields at the top of the page — and find that age down the left-hand side. The rows run from lunar age 18 at the top to lunar age 45 at the bottom, one row per year, with no gaps: all 28 rows the traditional chart carries are printed. Then find the lunar month of conception across the top, months 1 to 12, and run a finger along the age row until it meets that month’s column. The cell where row and column cross already holds the tradition’s answer, printed as a word — Boy on blue, Girl on pink.

Two checks keep a hand reading honest. First, count the grid: 28 age rows times 12 month columns is 336 cells, and the grid on this page has been verified cell by cell against the calculator’s own chart data — every one of the 336 cells in the printed table matches the value the engine looks up, so the chart you read by hand and the chart the calculator reads are the same chart. Second, count the split: across the whole grid, 165 cells read Boy and 171 read Girl — close to the even split you would expect of a table whose real-world record is about 50 percent. Neither check makes the tradition true; they simply confirm that the artefact on this page is complete and faithfully reproduced.

The printed chart is also interactive, in a small way: click any cell and the calculator at the top of the page loads that lunar age and lunar month as a direct lookup and shows what the chart says for it, with the row and column highlighted so you can see exactly where the answer came from. It is the hand reading, mirrored — useful when you want to test a neighbouring cell, for instance when a conception date sits near a lunar-month boundary and the month either side is worth a look, for curiosity’s sake.

Everything the traditional chart asks for starts with a single number: the mother’s lunar age at conception. The recipe has three steps. First, find the lunar year she was born in: if her birthday fell on or after Chinese New Year in her birth year, her lunar birth year is simply that calendar year; if her birthday fell before that year’s Chinese New Year, she was born at the tail of the previous lunar year, so subtract one. Second, find the lunar year of conception the same way, from the conception date and that year’s Chinese New Year. Third, apply the formula the tradition uses: lunar age = lunar year conceived − lunar year born + 1. The +1 is the traditional reckoning itself — a baby counts as one year old at birth — and the Chinese New Year step is why lunar age usually lands one or two years above Western age.

The worked examples below are the cases that catch people out. The first is this page’s own loaded example. The next two are a matched pair: two mothers born weeks apart in the same winter, a whole lunar year apart for life, because Chinese New Year 1990 fell on 27 January — between their birthdays. The last two are the sharpest edge case of all: babies born a day either side of Chinese New Year 2026 (17 February), who start life a full lunar year apart and carry that difference into every chart reading they will ever have.

Read the middle pair slowly, because it is the whole lesson. The mother born on 20 January 1990 arrived a week before that year’s New Year, so in the traditional reckoning she belongs to lunar 1989 — and she had already gained a year, along with everyone else, when the festival arrived days later. The mother born on 1 March 1990 belongs to lunar 1990. At any conception in the same lunar year their Western ages are identical, yet the chart puts them a row apart — 38 against 37 at a 2026 conception — and neighbouring rows often read differently. Neither mother has made an error; the tradition is working exactly as designed, and this is why a lunar-age calculator earns its keep: the boundary moves every year, falling between 21 January and 20 February, so no fixed “add one” or “add two” shortcut survives contact with a January or February birthday.

The second half of the lookup is the lunar month of conception. Real lunar months alternate 29 and 30 days and some years carry a leap month; the tradition as it is practised with this chart, and this page with it, counts in average months of 29.53 days from Chinese New Year. On that count, the day ranges are fixed: conception 0 to 29 days after New Year sits in lunar month 1, 30 to 59 days in month 2, and so on through the table below. The loaded example shows the count in action — 15 August 2026 falls 179 days after Chinese New Year (17 February 2026), which is six full average months gone, so the conception sits in lunar month 7. Near a range edge, treat the month as approximate: a day or two either way can move the reading to the neighbouring cell, which is one more reason the tradition’s answer is for fun.

Put the two halves together and the method is complete: a lunar age from the two New Year boundaries, a lunar month from the day count, and one cell of the traditional chart where that row and column meet. The calculator at the top of this page performs exactly these steps — no hidden adjustments, no extra inputs — and shows its working under the result, so a hand calculation from the tables on this page and the calculator’s reading can always be checked against each other.