Free Tools
Chinese Gender Predictor
A boy-or-girl guess from the legendary chart — based on mom's age and conception month, just for fun.
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How this works
Pick the mother's birth date and the month the baby was (or will be) conceived. That's all the tool needs — there is no year input, because the prediction only depends on the mother's age and the chosen month.
From the birth date, the tool works out a "lunar age": the mother's age in full years as of today, plus one. Adding one year is the traditional Chinese age convention, where a newborn is considered one year old. The conception month is used exactly as you picked it.
A simple rule then maps that age-and-month pair to Boy or Girl, in the spirit of the ancient chart that legend says was found in a 700-year-old royal tomb. The result updates instantly as you change the inputs, and the link in your address bar captures your inputs so you can share it.
This is an entertainment tool. The prediction has no scientific basis, and its actual accuracy is around 50% — the same as flipping a coin.
The math behind it
Full transparency: this tool uses a simplified heuristic inspired by the traditional Chinese gender chart — it is not the authentic 18–45 lunar-age by 12 lunar-month table lookup, and it performs no lunar-calendar conversion. It intentionally matches the ProbaBaby iOS app's implementation exactly, so the website and the app always give the same answer for the same inputs.
Step 1 — "lunar age": lunarAge = (full calendar years from the mother's birth date to today) + 1. The +1 is the Chinese age convention and is the only "lunar" element in the calculation. Note that the age is measured to today, not to the conception date. Step 2 — "lunar month": lunarMonth = the Gregorian conception month you selected (1–12), used unconverted.
Step 3 — the prediction rule has three branches. If lunarAge ≤ 21: an even month means Girl, an odd month means Boy. If lunarAge is 22–29: when the age and the month have different parity (one even, one odd) the result is Boy; when they match, Girl. If lunarAge ≥ 30: months 1–6 give Boy, months 7–12 give Girl.
Because the age is computed against today and the month is taken as-is, the conception year never enters the math — only the mother's age today and the chosen month matter. Websites that implement the traditional chart with a real Gregorian-to-lunar conversion will often produce different answers than this tool for the same inputs.
Frequently asked questions
It combines two numbers: the mother's "lunar age" (her age in full years as of today, plus one — the Chinese age convention) and the conception month (1–12). A three-branch rule then decides: at lunar age 21 or below, even months predict Girl and odd months Boy; at 22–29, mismatched age/month parity predicts Boy and matched parity Girl; at 30 or above, months 1–6 predict Boy and months 7–12 Girl.
Most other sites look the answer up in the traditional 18–45 lunar-age by 12 lunar-month table, often with a real Gregorian-to-lunar calendar conversion. This tool instead uses a simplified age-and-month parity rule that exactly matches the ProbaBaby iOS app, so the app and the website always agree — but they can disagree with lunar-table versions for the same inputs.
About 50% — the same as random chance or flipping a coin. Since a baby is either a boy or a girl, any method "works" roughly half the time. It has no scientific basis and is for entertainment only; it should never be used for medical decisions.
No. The calculation only uses the mother's age as of today (plus one, per the Chinese age convention) and the conception month you pick. The year never enters the math, which is why the tool doesn't ask for one.
Here it means the mother's age in full years measured to today, plus one — the traditional Chinese convention that counts a newborn as one year old. That +1 is the only lunar element: the tool does not convert any dates to the lunar calendar, and the "lunar month" shown is simply the Gregorian month you selected.