How the Chinese Gender Calendar Works

The Chinese gender calendar is a traditional chart used to predict a baby's sex based on two time-based inputs. It is commonly shared in families as a cultural curiosity rather than a medical tool.

The method compares the mother's lunar age with the lunar month of conception and then looks up the result on a grid. The outcome is presented as a boy or girl prediction.

While people enjoy the tradition, it is best understood as folklore. The calculator on this site automates the same steps so you can see how the chart is read.

What the Chinese Gender Calendar Is

The chart is a grid that pairs a mother's lunar age with the lunar month of conception. Each intersection gives a predicted outcome. The method is widely referenced in traditional storytelling and family conversations.

Its origins are usually linked to historical Chinese practices and the broader lunar calendar system. The emphasis is on tradition rather than evidence-based prediction.

Diagram showing lunar age and lunar month inputs feeding into a chart
Conceptual overview of the two inputs and how the chart produces a result.

The Two Inputs Used in the Chinese Gender Calendar

Mother's Lunar Age

Lunar age counts the time in the womb and increases at Chinese New Year rather than on a birthday. This usually makes the lunar age one to two years older than Western age.

Western AgeTypical Lunar Age
3031-32
3132-33
3233-34

Lunar Month of Conception

The Chinese lunar calendar follows moon cycles, so lunar months do not line up exactly with Gregorian months. A converter is needed to find the lunar month for a specific conception date.

Gregorian DateLunar Month (Example)
April 12, 2026Lunar Month 3
June 8, 2026Lunar Month 5
September 1, 2026Lunar Month 8

How the Prediction Is Made

The chart is read by finding the row for the mother's lunar age and the column for the lunar month of conception. The cell at their intersection shows the prediction.

Simplified sample chart showing boy and girl outcomes
A simplified example of the chart grid and how outcomes are displayed.
  • Calculate the mother's lunar age for the year of conception.
  • Convert the conception date to the corresponding lunar month.
  • Locate the age row and month column on the chart.
  • Read the prediction at the intersection.

Using a Calculator vs Reading the Chart Manually

A calculator handles the lunar conversions automatically, while manual chart reading requires careful lookup of lunar age and month. Both approaches follow the same underlying chart.

ApproachProsCons
CalculatorAutomatic lunar conversion, fast resultsLess visibility into each step
Manual chartTransparent steps, traditional approachProne to conversion errors

If you want a quick result, try the chinese gender predictor.

Common Misunderstandings

The chart is not a medical tool, and it does not replace genetic testing or ultrasound.

Lunar age is not the same as Western age, so using a birthday alone can produce an incorrect row.

For answers about accuracy, see the chinese gender calendar accuracy guide. For practical questions, visit the FAQ.

You can also explore how the lunar system works in our chinese lunar calendar guide.