Baby Gender Predictor & Chinese Gender Chart Calculator
A fun, interactive way to predict your baby’s gender using the ancient Chinese Lunar Calendar chart, plus the heart-rate and Mayan calendar folklore methods — all in one free tool. See how these traditions stack up against real medical accuracy too.
Predict Your Baby’s Gender
Enter your details below. This calculator blends three traditional folklore methods — it’s a fun keepsake, not a medical test.
Overall Lean: —
Based on how many of the methods below agree
Medically reviewed by Dr. Ruqaiya Khan, MD, FACOG
Board-certified OB-GYN. The medical accuracy claims on this page were reviewed on June 2026. The prediction tool above is presented as entertainment/folklore and is clearly labeled as such throughout. View reviewer credentials →
Folklore vs. Medical Accuracy — At a Glance
Here’s how each gender-prediction method compares in real-world accuracy. Folklore methods cluster around a coin-flip (50%), while medical methods are dramatically more reliable.
How the Chinese Gender Chart Works
The Chinese Gender Chart (also called the Chinese Gender Predictor or Chinese Lunar Calendar method) is said to be based on a centuries-old chart discovered near a royal tomb in Beijing. It cross-references the mother’s lunar age at conception with the lunar month of conception to produce a boy/girl prediction. Lunar age differs from your regular birthday age — it’s typically calculated as your age at conception plus one, since traditional Chinese age-counting begins at conception rather than birth.
It’s a beloved pregnancy tradition used by millions of expecting parents worldwide for fun gender-reveal parties and baby showers — but it has never been validated in a peer-reviewed clinical study, and the handful of analyses that have tested it found accuracy statistically indistinguishable from random chance.
The Heart Rate Myth
A widely repeated piece of pregnancy folklore claims that a fetal heart rate above 140 beats per minute predicts a girl, while a rate at or below 140 bpm predicts a boy. Obstetric research has specifically tested this claim — including a frequently cited study in the American Journal of Obstetrics and Gynecology — and found no statistically significant difference in heart rate between male and female fetuses at any stage of pregnancy. Heart rate is influenced by gestational age and the baby’s activity level, not sex.
The Mayan Calendar Method
Similar to the Chinese chart, the Mayan gender prediction method compares the mother’s age at conception with the lunar year of conception, using odd/even number rules to predict the baby’s sex. Like the Chinese chart, it is a cultural tradition rather than a scientifically validated method.
How Accurate Are the Medically Proven Methods?
| Method | Earliest Availability | Accuracy |
|---|---|---|
| NIPT (cell-free DNA blood test) | ~10 weeks | 99%+ |
| CVS (Chorionic Villus Sampling) | 11–13 weeks | ~99.9% |
| Amniocentesis | 15–20 weeks | ~99.9% |
| Anatomy Ultrasound | 18–20 weeks | ~95–99%* |
*Ultrasound accuracy depends on fetal positioning and operator experience at the time of the scan.
If you want a reliable answer rather than a fun guess, an anatomy ultrasound around 18–20 weeks is the most common and accessible option, while NIPT blood testing (originally designed to screen for chromosomal conditions) can reveal sex as early as 10 weeks with very high accuracy, when ordered by your provider.
Frequently Asked Questions
Is the Baby Gender Predictor Accurate?
Our baby gender predictor is designed for fun and entertainment, combining traditional folklore methods like the Chinese lunar calendar with playful heart-rate predictions. While many families enjoy comparing results, these methods are not scientifically proven, so they should never replace a clinical ultrasound or genetic test. If you’re also tracking symptoms, our Pregnancy Symptom Tracker can help. For evidence-based information on prenatal testing methods, see the American College of Obstetricians and Gynecologists resource on genetic testing. Whether you use our baby gender predictor for a fun baby shower game or just out of curiosity, remember it’s meant purely as entertainment.