Short Answer
The Chinese Gender Calendar is not considered a reliable way to predict a baby's sex. The best-known population-based research on the Chinese lunar calendar method found that it did not perform better than chance in any meaningful way.[1]
That means it is best understood as a traditional guessing method, not as a validated prediction tool.
Why Can It Feel Convincing?
One reason is simple: there are only two outcomes, boy or girl. When a method has only two possible answers, it can appear correct quite often even if it has no real predictive power.
Another reason is that people naturally remember the predictions that seemed right and forget the ones that were wrong. That can make a folklore method feel more accurate than it really is.
What Does the Research Say?
The most important study on this topic is a large population-based study published in Paediatric and Perinatal Epidemiology. It evaluated the Chinese lunar calendar method and concluded that it did not show useful predictive agreement beyond chance.[1]
That is the main reason the Chinese Gender Calendar should not be treated as a reliable way to determine fetal sex. Popularity and tradition do not change the fact that the method has not been scientifically validated as an accurate predictor.
Is the Chinese Gender Calendar Scientific?
No. It is better understood as a traditional or folklore-based method rather than a scientific one.
That distinction matters because many people encounter the chart early in pregnancy, when curiosity is high and medically reliable information may not be available yet. In that context, the chart can feel meaningful and exciting, but that is very different from being evidence-based.
What Methods Are More Reliable?
If you want a medically grounded answer, clinical methods are much more dependable than the Chinese Gender Calendar.
Cell-free DNA screening is widely used in pregnancy and can also provide fetal sex information. Guidance summarized by the Society for Maternal-Fetal Medicine describes cfDNA screening as highly useful in prenatal care, while also reminding patients that it is still a screening test rather than a diagnostic test.[2]
Research focused on prenatal cfDNA performance has also reported extremely high accuracy for fetal sex prediction in study settings.[3]
Ultrasound is also a much more reliable approach than folklore methods, and a recent systematic review and meta-analysis examined its effectiveness for fetal sex identification.[4]
So if your goal is to know the baby's sex as accurately as possible, the Chinese Gender Calendar should not be your main source.
Is It Still Worth Using?
Yes, if you use it in the right spirit.
The Chinese Gender Calendar can still be fun to try. It has cultural appeal, it is easy to understand, and it gives parents a playful way to engage with pregnancy curiosity.
But fun and reliability are not the same thing. Even if you use an online predictor to make the chart easier to read, that does not change the underlying accuracy of the traditional method.
Final Verdict
So, how accurate is the Chinese Gender Calendar?
Based on the best available evidence, not very. It is best treated as a traditional guessing method, not a reliable predictor.[1]
If you enjoy the tradition, there is nothing wrong with trying it. Just keep your expectations realistic.
References
Villamor E, et al. Accuracy of the Chinese lunar calendar method to predict a baby's sex: a population-based study. PubMed:
https://pubmed.ncbi.nlm.nih.gov/20618730/
Society for Maternal-Fetal Medicine. Prenatal Screening Using Cell-Free DNA.
https://s3.amazonaws.com/cdn.smfm.org/attachments/104/2162bd28b15f8044599722125c4733c2.pdf
Performance of prenatal cfDNA screening for sex chromosomes. PubMed:
https://pubmed.ncbi.nlm.nih.gov/37154148/
Effectiveness of prenatal ultrasound in fetal sex identification: a systematic review and meta-analysis. PubMed:
https://pubmed.ncbi.nlm.nih.gov/39798051/