What Is the Chinese Gender Predictor?
The Chinese gender predictor (also called the Chinese birth chart or Qing dynasty gender chart) is a centuries-old folk tradition that claims to predict whether a baby will be a boy or a girl using two inputs: the mother's age and the month the baby was conceived. This calculator reconstructs that chart using a parity rule based on the mother's lunar age and the lunar conception month. It is a cultural curiosity, not a medical tool.
How to Use It
Enter the mother's age at the time of conception and select the month conception occurred. The calculator converts the Gregorian age to a lunar (East-Asian) age by adding one year, then applies the chart's parity rule to produce a boy or girl prediction. For best alignment with the traditional chart, use the mother's lunar age and the lunar (Chinese) calendar month.
The Formula Explained
First we compute lunar age = Gregorian age + 1, reflecting the East-Asian custom where a baby is considered one year old at birth. We then add the conception month to the lunar age. If the sum is odd, the chart predicts a boy; if even, a girl. This parity approach captures the alternating pattern found across most cells of the historical chart.
$$\text{Gender} = \begin{cases} \text{Boy} & \text{if } \big[\left(\text{Mother Age}+1\right) + \text{Conception Month}\big] \bmod 2 = 1 \\[0.6em] \text{Girl} & \text{if } \big[\left(\text{Mother Age}+1\right) + \text{Conception Month}\big] \bmod 2 = 0 \end{cases}$$
Worked Example
A mother aged 29 conceives in March (month 3). Lunar age = \(29 + 1 = 30\). Sum = \(30 + 3 = 33\), which is odd, so the chart predicts a boy. Change conception to April (month 4) and the sum becomes \(34\) (even) — predicting a girl.
FAQ
Is the Chinese gender chart accurate? No. Studies show it performs no better than a coin flip. Use it for fun only.
Should I use lunar or Gregorian age? The traditional chart uses lunar age, which this tool estimates by adding one year to the Gregorian age.
What about the conception month? The chart was designed around the Chinese lunar calendar, so converting your conception date to the lunar month gives the most authentic result.
