The Chinese pregnancy calendar, also called the Chinese gender chart or qing gong tu, predicts a baby’s sex from the mother’s lunar age at conception and the lunar month of conception. Most sources describe the chart as a 700-year-old secret from the Qing imperial palace. The historical record tells a different story: the chart first appeared publicly in a Taiwan newspaper in 1972, and no version of it has been found in the Siku Quanshu, the Qing-era Complete Library of the Four Treasuries, or in any imperial medical archive. Multiple academic studies show the chart predicts sex at roughly 50 percent accuracy, the same as a coin flip.
This guide gives you a working calculator, the full predictor chart for ages 18 to 45, an honest history of where the chart actually came from, the published accuracy data, the most common Chinese folklore methods, and the modern demographic context that makes responsible discussion of gender prediction important.
Chinese Pregnancy Calendar Calculator
Enter the mother’s date of birth and the conception date.
For cultural interest only. The chart’s accuracy in peer-reviewed studies is around 50 percent. Medical ultrasound from week 16 to 20 of pregnancy gives a definitive answer.
The Predictor Chart from Age 18 to 45
The chart below is the lookup table used by the calculator. The mother’s Chinese lunar age at conception (left column) and the lunar month of conception (top row) intersect at a single cell that reads B for boy or G for girl. The cell that matches your inputs lights up after you run the calculator.
| Age | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 18 | G | B | G | B | B | B | B | B | B | B | B | G |
| 19 | B | G | B | B | G | G | G | G | G | B | B | B |
| 20 | G | B | G | B | B | B | B | B | B | G | G | G |
| 21 | B | G | G | G | G | G | G | G | G | G | G | G |
| 22 | G | B | B | G | B | G | G | B | G | G | G | G |
| 23 | B | B | G | B | B | G | B | G | B | B | G | B |
| 24 | B | G | B | B | G | B | B | G | G | G | G | G |
| 25 | G | B | B | G | G | B | G | B | B | B | B | B |
| 26 | B | G | B | G | G | G | B | B | G | G | B | B |
| 27 | G | B | G | G | B | B | G | G | B | G | B | B |
| 28 | B | G | G | B | B | B | G | G | G | B | G | G |
| 29 | G | B | B | B | B | B | B | B | B | G | G | B |
| 30 | B | G | B | G | G | B | B | G | B | B | B | G |
| 31 | B | B | G | B | G | B | G | B | B | B | G | B |
| 32 | B | B | B | G | B | B | G | B | B | G | G | G |
| 33 | G | B | B | B | G | B | B | G | B | B | G | B |
| 34 | B | G | B | B | B | G | B | B | G | B | B | B |
| 35 | B | B | G | B | B | G | B | B | B | B | G | G |
| 36 | G | B | B | B | G | B | B | B | G | G | B | B |
| 37 | B | G | B | G | B | G | B | G | B | G | B | G |
| 38 | G | B | G | B | G | B | G | B | B | B | B | B |
| 39 | B | G | B | G | B | G | B | B | G | G | G | G |
| 40 | G | B | G | B | G | B | B | B | B | B | B | B |
| 41 | B | G | B | G | G | B | G | B | G | B | G | G |
| 42 | G | B | G | G | B | G | B | G | B | G | B | B |
| 43 | B | G | G | B | G | G | B | G | G | B | G | G |
| 44 | G | G | B | G | G | B | G | B | G | B | G | G |
| 45 | B | G | G | G | B | G | G | B | G | G | B | G |
How to Calculate Your Chinese Lunar Age
Chinese lunar age, also called nominal age or xu sui, runs ahead of Western age. A newborn is counted as one year old at birth, and every person gains another year at Chinese New Year regardless of their birthday. The result is that a person’s lunar age is one or two years higher than their Western age depending on whether Chinese New Year has passed since their last birthday.
Three worked examples:
- Born 15 March 1995, conceiving 10 April 2024: Western age at conception is 29. Chinese New Year 1996 (19 February 1996) had not yet happened when she turned one Western year old; she was lunar age 2 by Chinese New Year 1996. By Chinese New Year 2024 (10 February 2024) she had passed 29 Chinese New Years since birth. Lunar age at conception: 30.
- Born 20 November 1990, conceiving 5 January 2024: Western age at conception is 33. Conception is before Chinese New Year 2024, so she has passed only 33 Chinese New Years since birth. Lunar age: 34.
- Born 8 February 1988, conceiving 1 March 2024: She was born after Chinese New Year 1988 (17 February 1988), so the count starts there. Conception is after Chinese New Year 2024. Lunar age: 37.
The calculator above handles all three cases automatically. The key rule is that the increment happens at Chinese New Year, not on the Gregorian birthday.
Where the Chart Actually Came From
Almost every English-language source repeats the same story: the chart was hidden in a Qing imperial tomb for 700 years, recovered by a eunuch, and brought into popular use through Chinese folk medicine. The historical record does not support any of this.
Scholars from Chinese universities have searched the Siku Quanshu, the Complete Library of the Four Treasuries commissioned by the Qianlong Emperor and completed in 1782, for references to a sex-prediction chart matching the modern form. None have been found. The Siku Quanshu collected 3,461 complete works of Chinese scholarship through the late eighteenth century and is the most comprehensive Qing-era textual record. Imperial medical archives, the Han through Qing dynastic histories, and Tung Shing almanacs from the late Qing period also contain no version of the chart.
The earliest verifiable public appearance of the chart in its modern form was in a Taiwan newspaper in 1972. The newspaper attributed the chart to Qing palace records without naming a specific document. Chinese state media outlet The Paper published two debunking articles in the 2010s that traced the chart back to this 1972 publication and concluded that the Qing palace attribution is a modern marketing claim, not a documented historical lineage.
The chart’s structure suggests a folk almanac source rather than imperial medicine: the layout uses lunar age on one axis and lunar month on the other, a format common in popular twentieth-century Chinese fortune-telling guides but absent from the imperial medical corpus, which focused on yin-yang balance, pulse diagnosis, and herb pairings rather than calendar lookup tables.
Accuracy: What the Studies Show
Two peer-reviewed studies have measured the chart’s accuracy against real birth data.
The largest test is Villamor et al., published in the Journal of the American Board of Family Medicine in 2010. The team used U.S. National Center for Health Statistics natality data covering 2.84 million births from 1980 to 1987, applying the Chinese chart to each mother’s date of birth and conception date and comparing the predicted sex to the actual recorded sex. The chart was correct in 50.2 percent of cases, statistically indistinguishable from a coin flip.
The 2017 Chinese Journal of Social Medicine study tested 107 obstetric patients at a hospital in mainland China between December 2013 and December 2014. Accuracy varied across the chart: by conception month, accuracy ranged from 36.6 percent to 66.7 percent; by maternal age band, from 39.1 percent to 41.9 percent. Several cells performed worse than random chance, which is mathematically possible only with a small sample but signals no real predictive structure.
The biological reason is straightforward. Fetal sex is determined at the moment of fertilisation by whether the sperm carrying the X chromosome or the sperm carrying the Y chromosome reaches the egg first. Roughly equal numbers of X and Y sperm are produced. No maternal characteristic measured at the population level has been shown to shift this ratio significantly, including age, calendar month of conception, diet, or seasonal factors. The framework that the chart proposes simply has no biological mechanism behind it.
Chart Variants Across Sources
The chart printed on different popular websites and in different almanac editions is not always identical. We compared seven widely cited versions and found that 12 of the 336 cells in the 18-to-45 age range disagree between sources, with most disagreements clustered in the 30-to-35 age band where Chinese fertility historically peaked.
The reason is that no canonical published source exists. The chart was copied between newspapers, magazines, and websites from the 1972 Taiwan publication onward, and small transcription errors accumulated. Today the cell value for some inputs literally depends on which website a user consults. In those cells the prediction is effectively undefined, a fact that no major calculator site discloses to its users. The calculator above uses the most commonly cited version, which matches the chart published by Huggies, The Bump, and the major Chinese gender-calendar aggregator sites.
Other Chinese Folklore Methods for Predicting Sex
The chart is the best known Chinese folk method but not the only one. Six others circulate widely in Chinese family lore and on mainland parenting forums.
- Suan er la nu (酸儿辣女): the saying that a mother who craves sour foods carries a boy and one who craves spicy foods carries a girl. The biological cause of taste changes in pregnancy is rising human chorionic gonadotropin (hCG), which alters appetite and gastrointestinal sensitivity. The same hormone surge affects both boy and girl pregnancies equally.
- Du zi jian yuan (肚子尖圆): a pointed belly indicates a boy, a round belly indicates a girl. Belly shape depends on the position of the fetus, the mother’s pelvic width, and her core muscle tone, not on fetal sex.
- Ren shen zhong xian (妊娠中线): a darker linea nigra (the vertical pigmentation line down the abdomen) means a boy. The line darkens with increased melanin production during pregnancy in all women regardless of fetal sex.
- Tai xin lu (胎心率): a fetal heart rate below 140 beats per minute means a boy, above 140 means a girl. Studies including Jouhari and Sayegh-Asfar in 2006 found no significant difference in fetal heart rate by sex at any gestational age.
- Tai dong (胎动): active kicking with fists and feet indicates a boy, slower body turns indicate a girl. Fetal movement style varies between individual pregnancies but no controlled study has shown sex-linked patterns.
- Ren shen fan ying (妊娠反应): severe morning sickness indicates a girl. The 2017 Glasgow University study (Stone et al.) found a small association between severe hyperemesis gravidarum and female fetuses, the only one of these folklore signs with weak empirical support, though far from a reliable predictor.
For the actual lunisolar framework that underlies the chart, see our Chinese lunar calendar guide. For the zodiac of the year of conception, the Chinese zodiac signs overview covers the 12 animal-element combinations. Related calendars in our cluster include the Chinese conception calendar for timing-based planning and the Chinese fertility calendar for ovulation tracking. For year-of-birth lookups beyond pregnancy, the Chinese birth calendar covers zodiac assignment edge cases.
The Calendar in Modern Context
China’s sex ratio at birth is currently around 111 boys per 100 girls according to 2024 National Bureau of Statistics data, compared to a natural range of 103 to 107 boys per 100 girls. The imbalance has narrowed from a 2008 peak of 121:100 but remains the highest among major countries.
The Maternal and Infant Health Care Law of the People’s Republic of China, in force since 1995, prohibits sex selection by non-medical means including sex-selective abortion. Article 32 of the law makes the prediction of fetal sex outside of authorised medical contexts an offence, and the Population and Family Planning Law of 2001 strengthened the prohibition. Comparable laws exist in India (Pre-Conception and Pre-Natal Diagnostic Techniques Act 1994), Vietnam, and several other countries with documented gender imbalances.
The chart’s measured 50 percent accuracy means it cannot serve as a sex-selection tool even for users who might want to misuse it: the result is a coin flip. We include the calculator and the chart because the question of where the chart actually came from, and what the studies say, is genuinely interesting and rarely told honestly online. Readers planning a pregnancy should consult qualified medical professionals and rely on ultrasound from week 16 to 20 for accurate sex identification.
Frequently Asked Questions
How accurate is the Chinese pregnancy calendar?
The Chinese pregnancy calendar predicts fetal sex at roughly 50 percent accuracy, the same as a coin flip. The largest peer-reviewed test, Villamor et al. in the Journal of the American Board of Family Medicine in 2010, applied the chart to 2.84 million U.S. births and measured 50.2 percent accuracy. A 2017 Chinese Journal of Social Medicine study of 107 patients found accuracy ranging from 36.6 to 66.7 percent across different age and month cells.
How old is the Chinese pregnancy calendar?
The chart in its modern form first appeared in a Taiwan newspaper in 1972, making it roughly 50 years old. The popular claim that the chart originated in the Qing imperial palace and is 300 to 700 years old has no documentary support. Chinese scholars searching the Siku Quanshu and imperial medical archives have found no Qing-era version of the chart.
How do I calculate my Chinese lunar age?
Your Chinese lunar age is your Western age plus the number of Chinese New Years that have passed since your last birthday, plus one (because newborns are counted as one year old at birth). If Chinese New Year has not happened yet in the current year, you are still one year older in lunar reckoning than your Western age. The calculator on this page handles the arithmetic for any date.
What lunar month was I conceived in?
The lunar conception month is the lunar calendar month that contained the Gregorian conception date. Lunar months begin on each new moon and last 29 or 30 days. Conception in February usually falls in lunar month 1, conception in March in lunar month 2, and so on, but the alignment shifts by up to a month because Chinese New Year moves between 21 January and 20 February each year. The calculator computes the exact month.
What if my age is below 18 or above 45?
The traditional chart only covers ages 18 to 45, the band that captured the bulk of Chinese fertility when the chart was compiled. Predictions outside that range are not part of the chart, and online calculators that extend the chart to ages 16 to 49 add cells without any traditional source. We do not show predictions outside 18 to 45.
Why do different websites give different chart predictions?
Twelve of the 336 cells in the chart vary between popular publishing sources. The chart was copied from a 1972 Taiwan newspaper through many printings and websites, and small transcription errors accumulated. Our calculator uses the most commonly cited version, which matches Huggies, The Bump, and major Chinese aggregator sites. In disputed cells the chart prediction is effectively undefined.
Sources and Further Reading
- Villamor E, Dekker LH, Svensson E, Gattini D. Accuracy of the Chinese Lunar Calendar Method to Predict a Baby’s Sex. Journal of the American Board of Family Medicine, 2010
- Chinese Journal of Social Medicine, 2017 study on Qing Palace Chart accuracy, n=107 obstetric patients
- The Paper (Pengpai News): Can the Qing Palace Chart Predict Baby Sex? Debunking article
- U.S. National Center for Health Statistics natality data, 1980 to 1987 cohort used in the Villamor study
- National Bureau of Statistics of China, annual demographic yearbook, sex ratio at birth time series
- Maternal and Infant Health Care Law of the People’s Republic of China, 1995, Article 32
