How the Chinese Gender Calendar works
The traditional chart pairs the mother’s Chinese lunar age at conception with the lunar month of conception. Lunar age follows a different counting convention from age in completed years, and lunar months can begin on different dates from Gregorian months.
What the accuracy study found
A 2010 study compared calendar predictions with records of 2,840,755 singleton births in Sweden. The predictions showed essentially no agreement beyond chance. The researchers also tested a website-style lunar conversion on a smaller sample and found no improvement.
Read the original study by Villamor and colleagues.
How it differs from the Chinese zodiac
The Chinese zodiac assigns an animal to a lunar year. A birthday near Lunar New Year can fall in the previous animal year. The birth chart described above uses lunar age and month for a separate folk tradition.
Explore the Chinese Zodiac Calculator or browse Zodiac Tools.