Chinese Gender Predictor

I had a girl and then a boy. Both times, I had a “feeling” I knew their sex early in the first trimester. Both times, I found out I was wrong at my second-trimester ultrasound.

Throughout pregnancy, you’ll hear one question more than any other: Boy or girl? Even if you’d be equally content with either, it’s hard not to be curious about the sex of the person growing inside you. While waiting to find out baby’s sex, plenty of parents and their families swear by prediction signs and methods, including Chinese gender calendar charts.

“I've seen grandparents and extended family eagerly offer their own predictions based on traditional Chinese beliefs,” says Dr. Meleen Chuang, MD, chief of obstetrics and gynecology at NYU Langone Hospital in Brooklyn, New York. "It's a fun way for different generations to connect."

But is the Chinese gender predictor calendar accurate or reliable? Ahead, learn more about why using the Chinese gender chart is mostly meant for fun, not actual answers.

Key Takeaways

• The Chinese gender calendar isn’t scientifically accurate. Chinese gender charts use Mom's lunar age and lunar month of conception to predict baby's sex. Research suggests it's right roughly half the time—no better than a coin flip.
• Your doctor can provide a trustworthy answer about baby’s sex. Genetic testing, including NIPT, is highly accurate. The second-trimester anatomy ultrasound is also reliable.
• Origins of the Chinese gender calendar: Legend has it that the Chinese gender predictor goes all the way back to the Qing Dynasty, but most researchers believe it’s a modern phenomenon.

What Is the Chinese Gender Calendar and How Does It Work?

The Chinese gender calendar (also known as a Chinese gender chart, Chinese gender predictor or Chinese birth chart) is a fun—though not at all reliable—method to predict baby’s sex. It compares an expecting mom’s age according to the Chinese lunisolar calendar—which is based on the movement of the sun and the phases of the moon—against baby’s lunar month of conception to form a “prediction.”

How Accurate is the Chinese Gender Predictor?

Research suggests that the Chinese gender predictor is about as accurate as a coin flip. In other words, don’t go shopping for baby clothes just yet.

The most widely cited study, published in 2010, tested a Chinese gender calendar’s predictions on 2,840,755 babies born in Sweden between 1973 and 2006. Researchers plugged a mother’s lunar age and month of conception—estimated using records of her last menstrual period—into the algorithm, then compared these results to actual birth records. They found the chart was right about half of the time. Basically, it was no better at predicting baby’s sex than random chance.

Real parents on using the Chinese Gender predictor chart

The Chinese gender predictor may not be entirely accurate, but plenty of real parents love to try it regardless. Here’s what a few moms thought about using the Chinese gender calendar for their own pregnancies:

• “With my son it said boy, and he's a boy…it says girl this time! I also thought my son was a girl until the first time I saw him at 13 weeks. I think this baby’s a girl too, so maybe the same thing will happen? I don’t know, but for some reason that chart really excited me! If it's a girl, I have so much shopping to do!” - ajdmama, The Bump community member
• "It was wrong for me. NBD, though—my baby girl is cool AF." — Amanda J.
• "I used it and it was right both times (two girls).” — Lauren W., mom of two
• "Didn’t work for me. Every single prediction said we were going to have a boy for our third child, but we were blessed with another girl." — Jennie T., mom of three
• "I didn't use it (and didn't find out gender before birth), but I just checked it and it was right. I know it's a 50/50 chance, but I was still impressed." — Julianne C.
• "It didn’t work for me! It said I was having a girl, and we’re having a boy." — Gabby W.
• "Used it for fun while I was pregnant both times. First was right, second was wrong (times two…twins!)." — Jen G., mom of three

What’s the History and Origins of the Chinese Gender Calendar?

In Chinese, the gender calendar is often called the "Qing-palace table,” says Dr. Yang Li, PhD, an assistant professor at the University of Wisconsin-Madison who specializes in the history of modern Chinese medicine. Legend has it that the Qing Dynasty imperial family relied on the Chinese gender chart for the gender selection of sons, who were favored for the work and money they could provide their families as well as for carrying on the family lineage.

Another tale says the Chinese gender predictor was found stored in an ancient royal tomb. But with a bit more digging, testimony from contemporary experts and our own fact-finding mission, we couldn’t find hard evidence to back either history.

Dr. Li says she hasn’t found any definitive historical evidence to support the Qing Dynasty theory. In fact, the original document “would likely have had a more specific title describing its purpose or method,” she says, adding that the chart also doesn’t appear to follow the logic or calculations of classical traditional Chinese prognostication methods like yin-yang or the five elements. Dr. Li believes the chart may therefore be a relatively recent phenomenon, “circulated primarily through popular media and the internet in recent decades.”

Historically, traditional Chinese calendars had a very different purpose. Most of the world today relies on the Gregorian calendar, which originated in ancient Rome, to track time. Numerous Asian countries, however, still use the Chinese lunisolar calendar to plan traditional festivals.

Circa 2,000 years ago, Chinese rulers regularly issued astrological calendars based on observations of the sky, explains Dr. Margaret Ng Wee-Siang, PhD, an associate professor at the College of Wooster who specializes in the history of Eastern medicine. These calendars were used to predict weather patterns, storms, eclipses and seasonal patterns, as well as keep time and “harmonize one’s body with the cosmic rhythm,” she says.

Core ideas in the lunisolar system include yin and yang (the two complementary forces of life) and wuxing (the “five phases” underpinning cosmic processes, associated with the five elements of water, earth, wood, fire and metal).

Traditional Chinese medicine did feature birth charts, known as chantu, dating back more than 1,000 years to the Song dynasty. These charts were updated on the first day of each month and posted on a mother’s birthing room to determine which direction she should face during delivery, explains Dr. Ng Wee-Siang, who researches the history of childbirth in East Asia. She says the modern iteration found online is “too simple, and it doesn't coincide with anything about Chinese calendars.”

Alternative Ways to Find Out Baby's Sex

The Chinese calendar to know gender can be a fun exercise—but there are far more reliable ways to find out baby’s sex:

• The most reliable ways to learn baby’s sex is with noninvasive prenatal testing (NIPT), which analyzes fragments of your baby’s DNA found in a sample of your blood. This screening test, which can be done as early as 10 weeks of pregnancy, “is more than 99 percent accurate in most singleton pregnancies,” says Dr. Chuang.
• You’ll also get a reliable result at your second trimester anatomy ultrasound, usually performed between 18 and 22 weeks of pregnancy.
• Diagnostic tests, including chorionic villus sampling (CVS) and amniocentesis, are also highly accurate at determining fetal sex. “These procedures are performed only when medically indicated, not simply to learn the baby's sex,” explains Dr. Chuang.

Other methods predict baby’s sex for fun more than any real insight. For example, some people examine pregnancy cravings (sweets for girls, salty and sour for boys), analyze bump position (high for girls, low for boys) or swing a ring on a string above your bump (back and forth for girls, around in circles for boys). Others look for clues in changes in appetite, the severity or duration of morning sickness or even sleep patterns.

While these methods aren’t scientific, they “can be a fun and meaningful part of the pregnancy experience,” says Dr. Chuang. “I've personally tried and have been wrong with two out of my three children.”

To Sum It Up

The Chinese gender calendar claims to predict baby’s sex using a mother’s lunar birth year and baby’s lunar month of conception. Historians say the methods found online today don’t appear to originate from traditional Chinese medicine, and research suggests that the Chinese gender predictor is about as accurate as random chance. But the method can be a fun way to connect with friends, family and baby.

How We Developed This Article

Parents-to-be are often eager to find out baby’s sex—whether the method is scientifically accurate or not. To learn about the Chinese gender calendar—a fun way to guess baby’s sex, but not a substitute for accurate prenatal testing—we spoke with an ob-gyn and two academics who specialize in Eastern medicine. We also consulted sources including Encyclopedia Britannica. Finally, we spoke with, and searched The Bump community forums for, real moms who’ve tried the Chinese gender chart themselves.

After editing, this article was vetted through fact-check and reviewed by our ob-gyn medical reviewer. Learn more about how we ensure the accuracy of our content through our editorial and medical review process.

About the author: Colleen de Bellefonds is a Paris-based health and science journalist and mom. After two pregnancies, she learned that the best way to truly know what baby’s sex will be is to ask your doctor.

Plus, more from The Bump:

Your Complete Guide to Prenatal Testing

Is the Shettles Method Legit?

How to Deal with Gender Disappointment