How Does a Chinese Conception Calendar Work?

Chinese legend posits that a woman can predict the gender of a baby using the Chinese conception calendar based on two criteria: the woman’s age and the month of conception, says the Baby Center. The rationale behind the calendar is that women of a given age are highly likely to give birth to children of the same gender.

To effectively use the calendar, women should adopt their lunar age based on the lunar calendar that the Chinese use, says Pregnancy and Baby. An online Gregorian-Chinese calendar converter helps determine the month of conception based on the lunar calendar. The chart may be color-coded or use letters to indicate a boy (B) or girl (G). The woman’s age appears along the top of the chart while the months of conception are down the side.

Users of the chart scroll down the chart based on their age at conception to find the point of intersection with the month of conception, which provides a prediction of the baby’s gender, reports Pregnancy and Baby. No scientific backing exists to prove the accuracy or reliability of the calendar, although some reports claim the centuries-old method has a high accuracy, according to Expectant mothers can use the chart as a fun tool for guessing a baby's gender, advises Pregnancy and Baby.