A centuries-old tradition, just for fun: enter your birth date and when you conceived to see whether the Chinese gender calendar guesses boy or girl.
Not sure? Use your estimated ovulation date, or the first day of your last period plus about 2 weeks.
Find your lunar age (left) and lunar month of conception (top). Blue = boy, pink = girl. Run the calculator above to light up your square.
| Lunar age | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 18 | G | B | G | B | G | B | G | B | G | B | G | B |
| 19 | B | G | B | G | B | G | B | G | B | G | B | G |
| 20 | G | B | G | B | G | B | G | B | G | B | G | B |
| 21 | B | G | B | G | B | G | B | G | B | G | B | G |
| 22 | G | B | G | B | G | B | G | B | G | B | G | B |
| 23 | B | G | B | G | B | G | B | G | B | G | B | G |
| 24 | G | B | G | B | G | B | G | B | G | B | G | B |
| 25 | B | G | B | G | B | G | B | G | B | G | B | G |
| 26 | G | B | G | B | G | B | G | B | G | B | G | B |
| 27 | B | G | B | G | B | G | B | G | B | G | B | G |
| 28 | G | B | G | B | G | B | G | B | G | B | G | B |
| 29 | B | G | B | G | B | G | B | G | B | G | B | G |
| 30 | G | B | G | B | G | B | G | B | G | B | G | B |
| 31 | B | G | B | G | B | G | B | G | B | G | B | G |
| 32 | G | B | G | B | G | B | G | B | G | B | G | B |
| 33 | B | G | B | G | B | G | B | G | B | G | B | G |
| 34 | G | B | G | B | G | B | G | B | G | B | G | B |
| 35 | B | G | B | G | B | G | B | G | B | G | B | G |
| 36 | G | B | G | B | G | B | G | B | G | B | G | B |
| 37 | B | G | B | G | B | G | B | G | B | G | B | G |
| 38 | G | B | G | B | G | B | G | B | G | B | G | B |
| 39 | B | G | B | G | B | G | B | G | B | G | B | G |
| 40 | G | B | G | B | G | B | G | B | G | B | G | B |
| 41 | B | G | B | G | B | G | B | G | B | G | B | G |
| 42 | G | B | G | B | G | B | G | B | G | B | G | B |
| 43 | B | G | B | G | B | G | B | G | B | G | B | G |
| 44 | G | B | G | B | G | B | G | B | G | B | G | B |
| 45 | B | G | B | G | B | G | B | G | B | G | B | G |
The Chinese gender chart — sometimes called the Chinese gender calendar or Chinese birth chart — is a piece of pregnancy folklore that claims to predict whether you're having a boy or a girl. According to legend, the original was discovered in a royal tomb and is roughly 700 years old, supposedly built on traditional ideas like Yin and Yang, the Five Elements and the lunar calendar. It's been passed around for generations and, in the internet age, has become a favorite lighthearted ritual during early pregnancy.
We'll be upfront from the start: this is entertainment, not medicine. It's a fun tradition to try at a gender reveal or to share with family — but it can't actually tell you your baby's sex. Think of it the way you'd treat a horoscope: enjoyable, not evidence.
The method uses two inputs: the mother's lunar age at the time she conceived, and the lunar month of conception. A common way to express the rule is a simple formula:
49 + (lunar month of conception) − (lunar age at conception) → an odd number is said to mean boy, an even number girl.
That formula is exactly what generates the grid above — every square is just the result of this calculation. Our calculator estimates your lunar age (your age at conception plus one, following the traditional reckoning) and uses your conception month, then lands you on the matching square. Everything runs in your browser; nothing you enter is stored or sent anywhere.
No — not beyond chance. Because a baby's sex is essentially a 50/50 outcome, any method will look "right" about half the time, and the Chinese gender chart is no exception. When researchers have compared its predictions to babies' actual sex at birth, they've found no real correlation. In plain terms: it performs about as well as flipping a coin. So enjoy it, screenshot it, tease your partner with it — just don't paint the nursery based on it.
If you want a prediction you can actually trust, the reliable options are all medical:
| Method | When | Reliability |
|---|---|---|
| Chinese gender chart | Anytime (for fun) | ~50% — no better than chance |
| NIPT / cfDNA blood test | From about 10 weeks | Very high for sex; also screens for chromosomal conditions |
| Anatomy ultrasound | Usually 18–20 weeks | High, though baby's position can obscure the view |
| CVS / amniocentesis | 1st–2nd trimester | Definitive — but diagnostic tests done for medical reasons, not curiosity |
Two quirks of the traditional Chinese calendar trip people up. First, lunar age: in the traditional system a baby is considered one year old at birth and adds a year at Chinese New Year rather than on their birthday, so a person's lunar age typically runs one to two years ahead of their Western age. Second, lunar months don't line up neatly with the Western calendar — the Chinese New Year falls somewhere between late January and mid-February, so the lunar month of conception can differ from the Western one.
For simplicity, this calculator approximates lunar age as your age at conception plus one, and uses your Western conception month. Purists convert both precisely, but since the chart has no predictive power either way, the approximation is perfectly fine for a bit of fun.
Traditions like this are lovely precisely because they're not serious. Use the chart as a playful prompt at a baby shower, pair it with other old wives' tales (the ring test, the way you're "carrying," cravings) and see how many agree, or save your result to compare with your ultrasound later. Whatever the chart says, and whatever you're having, the only thing that truly matters is a healthy pregnancy — and that's a conversation for you and your provider, not a centuries-old grid.
Honestly? It's about as accurate as a coin flip — roughly 50%. The chart is centuries-old folklore, not science, and studies that have tested it find no real ability to predict a baby's sex beyond chance. It's a fun tradition to try, but the only reliable ways to know are medical: an anatomy ultrasound (usually around 18–20 weeks), or non-invasive prenatal testing (NIPT) from about 10 weeks.
The traditional method uses two numbers: the mother’s "lunar age" when she conceived and the lunar month of conception. One common way to express it is the formula (49 + lunar month − lunar age): an odd result is said to mean a boy, an even result a girl. This calculator does that math for you and highlights your square on the chart.
In the traditional Chinese system, a baby is considered 1 year old at birth and gains a year at Chinese New Year rather than on their birthday, so a person's lunar age is usually about one to two years older than their Western age. This calculator approximates your lunar age as your age at conception plus one year, which is the common simplification. It's an estimate — but since the method isn't scientific anyway, small differences don't change much.
According to legend, the original chart was discovered in a royal tomb and is around 700 years old, said to be based on traditional ideas like Yin and Yang, the Five Elements and the lunar calendar. There’s no historical or scientific evidence behind its predictions, but it has stayed popular as a lighthearted pregnancy tradition and a fun gender-reveal prompt.
Reliable options are all medical. NIPT (a blood test, also called cfDNA screening) can indicate sex from about 10 weeks. The mid-pregnancy anatomy ultrasound, typically at 18–20 weeks, can often show it. Diagnostic tests like CVS and amniocentesis determine it definitively when they’re done for other reasons. Ask your provider which options make sense for you.