Boy or girl?

Is the Chinese gender calendar accurate?

Checked against the sources listed on this page. Not reviewed by a clinician. Last updated 5 November 2026. How we check.

Myth

No. When tested on real birth records, it performed no better than guessing.

The calendar predicts sex from the mother’s lunar age and the lunar month of conception. It has a 50% chance of being right, and that is exactly how it performs.

Any calendar or chart that uses dates alone can’t know which sperm fertilised the egg.

References

  1. Villamor E et al. Accuracy of the Chinese lunar calendar method. Paediatric and Perinatal Epidemiology, 2010

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More boy or girl? myths

Myth

Does carrying high mean a girl and carrying low mean a boy?

No. The shape and height of a bump depend on your muscles, body shape, how many pregnancies you’ve had and the baby’s position, not the baby’s sex.

 Myth

Does a heart rate over 140 mean it’s a girl?

No. Studies comparing early heart rates in boys and girls found no meaningful difference. Heart rate depends mostly on gestational age.

 Partly true

Does bad morning sickness mean you’re having a girl?

There’s a small statistical link between severe sickness and girls, but it can’t predict the sex of any one baby.