The Chinese gender predictor: folklore and evidence

What is the Chinese gender predictor?

The Chinese gender predictor, also called a Chinese gender calendar or baby gender chart, is a folklore chart that matches the mother's age at conception with the lunar month of conception to give a boy-or-girl prediction. The calculator on this page works out the calendar details from ordinary dates, so you do not need to convert them yourself.

How to use the calculator

Enter the mother's birth date and the conception date in the ordinary Gregorian calendar. The tool converts both dates automatically and shows the mother's nominal age at conception and the lunar month used for the chart lookup.

Use the original dates without adjusting them first. You do not need to enter a lunar birthday or add a year to the mother's age.

What does “lunar age” mean here?

Here, “lunar age” means nominal age: a count of Chinese calendar years entered, rather than completed birthday anniversaries. The tool calculates it as:

Nominal age = Chinese calendar year at conception − Chinese calendar year at birth + 1

Both year values come from the converted dates, not simply the Gregorian years you entered. This matters around Chinese New Year, when a Gregorian date can still belong to the preceding Chinese calendar year. Nominal age is therefore not always the mother's ordinary age plus one.

The age used is her nominal age at conception, not her age today or at the baby's birth.

How to read the optional chart

The optional chart lets you look up the same result yourself. Find the mother's displayed nominal age in the rows down the side, then find the displayed lunar conception month in the columns across the top. The box where that row and column meet contains the chart's boy-or-girl prediction.

For example, a nominal age of 29 and a conception date in lunar month 6 means reading row 29, column 6. Use the lunar month shown by the calculator: lunar month 6 is not necessarily June.

Why might there be no result?

This version uses one modern chart covering nominal ages 19–41, inclusive. There is no chart entry for an age outside that range.

It also gives no result for conception in a leap month. A leap month repeats an existing lunar month number, but it is a separate month. This chart has no rule for handling leap conception months, so the calculator does not substitute the ordinary month with the same number.

How accurate is the Chinese gender predictor?

A 2010 population study tested the Chinese lunar calendar prediction method using 2,840,755 singleton births in Sweden from 1973 to 2006. Its predictions performed no better than chance. Individual correct guesses do not establish that the method can reliably predict a baby's sex. Treat the result as a guessing game, not a medical test or a basis for pregnancy decisions.

Does a 2026 or 2027 chart work differently?

This calculator uses the same chart for 2026, 2027 and other years. The year matters when converting the dates and calculating nominal age; it does not introduce a new set of boy-or-girl labels. Different dates may lead to a different box in the same chart.

Origins and folklore

The chart data used here comes from the modern QingGong software project, while the chart’s historical origins remain uncertain.