The short answer
No: every test of the chart we found came out no better than chance. Tested on 2,840,755 Swedish births, it was “no better at predicting the sex of a baby than tossing a coin.” At a Boston hospital, it was right for about half of 38,394 babies. Boys and girls are born in nearly equal numbers, so any guess comes true about half the time.
Below: how to read the chart, the royal-tomb story, what each test found, the “2026” and “2027” charts, and what does tell boy from girl.
The Chinese gender chart, also called the Chinese gender calendar or predictor, is a grid that claims to tell you whether you’ll have a boy or a girl. You look up two things: the mother’s age and the month the baby was conceived, both counted on the Chinese lunar calendar (Villamor and colleagues, 2010).
In China it’s known as the Qing Palace Table (清宫表), and it’s popular there too. In mainland China, it was consistently a more popular search on Baidu than ultrasonography in the years up to 2021, a 2023 study in American Anthropologist found. There, the authors note, it is “currently illegal to use ultrasonography to identify fetal sex.” People “often exhibit interest in the predictive accuracy” of the chart, the authors wrote, “even though they may not necessarily believe in it” (Hong and Zinin, 2023).
That’s a good spirit to play it in: as a folk tradition and a game, like the old wives’ tales in our boy or girl quiz. A calendar can’t see your baby. A scan or a blood test detects the baby’s sex, from anatomy or chromosomes.
Chart sites and the researchers who tested the chart describe the same three steps (Villamor and colleagues, University of Michigan):
Converting dates takes “non-trivial calendrical calculations,” the Swedish researchers noted, and various websites offer to do it for you.
Sites don’t count the age the same way. SneakPeek’s blog says to “Add 1 to your age at conception” (SneakPeek, 2025). The Bump gives a formula: “the current year in the lunar calendar, minus your birth year in the lunar calendar, plus one” (The Bump, 2026). For part of each year, that formula comes to 2 more than your age, not 1. A year’s difference moves you to another line of the grid, and the square there may say the opposite.
The origin story comes in several versions. The Vancouver doctors who tested the chart wrote that it was “supposedly discovered in a Royal tomb near Beijing.” The Swedish team cited a website saying it was “buried in a tomb near Beijing for almost 700 years.” Other versions tie it to the Qing dynasty’s imperial court (The Bump). Others say it first appeared in a newspaper in the 1970s: in Taiwan, according to one chart site, or in Hong Kong, according to another (Chinese Fortune Calendar, SneakPeek).
We couldn’t find a record that confirms any of them, and neither could others who looked. The Vancouver doctors “were unable to determine its authenticity” (Ostler and Sun, CMAJ, 1999). Even the site that credits a Taiwanese newspaper calls the tomb story “not true.”
The Bump, in an article updated in 2026, quotes two historians of medicine. Yang Li, who studies the history of modern Chinese medicine at the University of Wisconsin–Madison, “hasn’t found any definitive historical evidence” for the Qing story. She thinks the chart may be a relatively recent arrival, “circulated primarily through popular media and the internet in recent decades” (The Bump).
Chinese medicine did have birth charts, called chantu. They date back more than 1,000 years, to the Song dynasty, and were posted in the birthing room to show which direction a mother should face during delivery, The Bump reports. Margaret Ng Wee-Siang, a historian of Eastern medicine at the College of Wooster, says the chart found online today is “too simple, and it doesn’t coincide with anything about Chinese calendars.”
We found five tests that checked the chart’s answers against each baby’s actual sex. In date order:
In Sweden, accuracy didn’t change with the year of conception, the mother’s age, her education, her body mass index (BMI) or how many times she’d given birth.
There is no information on the rationale behind the chart and we couldn’t think of a biological basis for it.
Eduardo Villamor, lead author of the Swedish study, University of Michigan, 2010
If the chart got your family wrong, was it the conversion? The tests say no. The Swedish team re-ran the chart with Western ages and months, as if someone had skipped the conversion, and the results didn’t substantially change. They also entered 1,000 randomly chosen mothers’ details into the most popular chart website, without knowing each baby’s sex. Its answers matched the babies no better than chance. In Boston, the chart scored about 50% with the mother’s Western age and about 50% with her lunar age.
Because boys and girls are born in nearly equal numbers. In Sweden, slightly more boys than girls are born every year: about 105 to 107 boys for every 100 girls, Statistics Sweden says (Statistics Sweden). In the U.S., the figure stayed between 1,046 and 1,059 boys per 1,000 girls from 1940 to 2002, the CDC’s National Center for Health Statistics reported (CDC). That’s about 51 boys in every 100 babies.
A coin, a chart or any guess that ignores the baby will be right about half the time.
Two researchers found 114 recorded predictions of a baby’s sex in historical Chinese records, made by various methods. The vast majority were written down as right.
With three children, about 1 in 8 families would see a coin come up right all three times. That family has a great story about the chart.
In the texts handed down, over 90% of predictions were recorded as right. Since chance alone gives about 50%, Hong and Zinin concluded that about 90% of the failed predictions were “either not recorded or fabricated as successes.” Failed predictions in everyday stories “may simply be ignored and not talked about,” they write. Predicting a baby’s sex is a human habit, not a Chinese one: it “has been a common practice in many human societies,” they note.
Chart sites have claimed far more. The University of Michigan noted website claims of “up to 93 percent,” and the Boston abstract cited claims of 93% to 99%. None of the tests came close.
Search for the chart and you’ll find “2026” and “2027” editions. It’s the same chart. It takes only two things, the mother’s lunar age and the lunar month of conception, so there’s no year in it to update. Even SneakPeek, which sells an at-home gender blood test, says the 2025, 2024 and later charts are “one and the same.”
What changes each year is the calendar. Lunar months start on different Western dates from year to year. Lunar New Year is the first day of the first lunar month. It fell on February 17 in 2026 and falls on February 6 in 2027, the Hong Kong Observatory’s tables show (2026, 2027). So a conception on February 10 counts as the 12th lunar month in 2026, but the 1st lunar month in 2027.
A dated page can help with that year’s conversion. It can’t make the chart more accurate: in the Swedish test, accuracy didn’t change with the year of conception, across 34 years of births.
These read the baby, not the calendar, though none is 100% sure. When can you find out your baby’s gender? puts every option on one timeline.
Collecting predictions for fun? The heart-rate tale, Ramzi theory and skull theory each get a guide that weighs the research. Nub theory is different: it reads an early scan, and studies have tested it, though a guess from a photo isn’t the same test.
Your date stays on this device. We never see it.
Trade the lunar calendar for your due date: the planner shows which of our sessions you could book now and which open next. What you type stays on your device.
The chart always has an answer. We don’t always, and our promise says what happens then: “If we can’t tell with confidence, we don’t guess. You come back, and the second look costs nothing.” No ultrasound can promise 100%.
At our studio in Glendale, Los Angeles County, our Gender Confirmation is a 2D scan, “the classic black-and-white picture,” with 8 black-and-white prints. We book from 13 weeks, and we’re surest from 15. If you can wait until 15, do: we’re more confident, and a second look is less likely. Once we have a clear view it can be over in 2 minutes. If your baby is being shy, we take longer.
It’s a keepsake, not a medical exam: it doesn’t replace the anatomy scan or any appointment with your doctor or midwife. Nor does it check your baby’s anatomy or health. The FDA and the AIUM discourage scans done only for keepsakes (FDA, AIUM); you can read what each says in Safety, in plain words. When you’re ready for a look, see finding out from 13 weeks, confirming what you’ve been told and prices.
No more than a coin toss. Tested on 2,840,755 Swedish births from 1973 to 2006, it was “no better at predicting the sex of a baby than tossing a coin.” At Massachusetts General Hospital in Boston, it was right for about half of 38,394 babies delivered from 1995 to 2008.
You look up the mother’s lunar age at conception and the lunar month of conception, both converted from Western dates to the Chinese lunar calendar. The square where they meet on the grid says boy or girl. In every test we found, that answer was no better than chance.
Traditional Chinese counting makes a baby 1 year old at birth and adds a year at each Lunar New Year. So your lunar age is 1 or 2 years more than your age in years, except for some women born in late January or February. Chart sites simplify this in different ways, so two sites can give two answers. In tests, the chart was no better than chance either way.
No, the chart is the same every year. What changes is the lunar calendar used to convert your dates: the Hong Kong Observatory’s tables put Lunar New Year on February 17 in 2026 and February 6 in 2027. In a Swedish test of births from 1973 to 2006, the chart’s accuracy didn’t change with the year.
Chance, as far as the tests can tell. Boys and girls are born in nearly equal numbers (in the U.S. and Sweden, about 51 in every 100 babies are boys), so any guess that ignores the baby is right about half the time. Families it worked for have a story to tell, and misses are easy to forget.
Its origin isn’t documented. One story says it was found in a royal tomb near Beijing after almost 700 years, and another that the Qing court used it. Doctors who tested the chart couldn’t confirm the first, and a historian of Chinese medicine has found no definitive evidence for the second. She thinks it may have spread mainly through popular media and the internet in recent decades.
Gender determination
At-home kits look for a boy’s DNA in your blood. Makers claim 99% or more from 6 or 7 weeks (2026); a 2011 review found lab tests before 7 weeks unreliable.
Gender determination
Gender disappointment is sadness or guilt about your baby’s sex. Charities call it common, and it doesn’t mean you won’t love your baby. What helps.
Gender determination
In the first trimester, the NIPT blood test is surer than a scan for sex. Later, medical scans are highly accurate too. Mismatch? Tell your doctor or midwife.
Same-day appointments are often available. Pick a time online, or call and we’ll find one together.