Baby Gender Predictor
Chinese Calendar Method — Just for fun!
Results are estimates only. Consult your healthcare provider. This is entertainment only. Not medically accurate.
About the Chinese Gender Calendar
The Chinese Gender Calendar (also called the Chinese Birth Chart) is an ancient method said to predict a baby's gender based on the mother's lunar age at conception and the lunar month of conception. It has been used for centuries, though it has no scientific basis.
Studies suggest it predicts gender correctly about 50% of the time — the same as chance. Use it for fun, not as medical information!
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What is the Chinese Gender Predictor?
The Chinese Gender Predictor — sometimes called the Chinese Lunar Calendar Method — is a traditional chart said to predict a baby's sex based on the mother's age at conception and the month of conception. The chart itself dates back several hundred years and was historically used in China as a folk method of gender prediction. Today, it is widely shared online as a fun, curiosity-driven tool. It is not a medical test, and it has no scientific basis for predicting gender.
How accurate is it?
Scientific studies that have tested the Chinese Gender Predictor against actual birth outcomes have found that it performs at roughly chance level — around 50% accuracy, which is what you would expect from a coin flip. A 2010 study published in the journal Paediatric and Perinatal Epidemiology specifically examined the chart and found no predictive validity. This is an important distinction: the predictor can be a fun conversation-starter or light-hearted tradition, but it should not be used to make decisions about baby names, nursery colours, or anything else.
How is a baby's sex actually determined?
The biological sex of a baby is determined at the moment of fertilisation by the sex chromosomes carried in the sperm. Every egg contains an X chromosome; sperm can carry either an X or a Y chromosome. If a Y-carrying sperm fertilises the egg, the embryo is typically XY (male); if an X-carrying sperm fertilises the egg, the embryo is XX (female). The probability of each outcome is approximately 50%, regardless of the mother's age or the time of year.
When can you find out the actual sex?
There are several medical methods for determining the baby's sex during pregnancy. Non-invasive prenatal testing (NIPT) — a blood test that analyses cell-free fetal DNA in the mother's bloodstream — can detect sex chromosomes as early as 10 weeks with very high accuracy. The anatomy scan ultrasound at around 18–20 weeks can often show the genitalia, though this depends on the baby's position. Diagnostic tests like chorionic villus sampling (CVS, at 10–13 weeks) and amniocentesis (at 15–20 weeks) provide definitive chromosomal information but carry a small procedural risk.
What about sex vs. gender?
Medical scans and genetic tests identify biological sex (chromosomal and anatomical characteristics), not gender identity. Gender is a social and psychological identity that develops over a person's lifetime and may or may not align with the sex assigned at birth. The Chinese Predictor and this tool refer to the traditional binary male/female distinction used in the folk chart — nothing more.