BaZi Chart Calculator
Enter a birth date and hours to build the four pillars — year, month, day pillar and hour pillar. Free, no account, and pure calculation: the same birth data always produces the same chart, including the same da-yun start age.
Birth details
What a BaZi chart contains
A BaZi chart — the Four Pillars of birth — turns a birth moment into eight characters: a Heavenly Stem and an Earthly Branch for the year, month, day and hour. The stem of the day pillar is the Day Master, and everything else in the chart is read in relation to it.
The day stem identifies the Day Master. The birth time, using the selected time convention, determines the hour branch; the day stem and hour branch together determine the hour stem. An unknown birth time leaves the hour pillar unresolved.
Hidden stems are the stems contained within a branch. Their Ten God roles are calculated relative to the Day Master. People born on the same date can have different hour pillars when their birth times differ.
The pillars, hidden stems and Ten Gods are calculated. The overview and other written readings are generated from those chart facts. The reading explains the calculated chart; it does not change its pillars.
Da-yun: the ten-year luck cycles, start age and luck year
The da-yun luck cycles are built from the month pillar and run forward in ten-year steps. Which direction they run depends on the year stem and gender, and where they begin — the start age — is counted from the birth date to the nearest solar term, so it is rarely a round number. This chart prints the start age next to every cycle rather than assuming everyone starts at ten.
Inside a cycle, each luck year adds one more stem and branch on top. A luck year is read against the same Day Master as the natal chart, which is why the same year lands very differently on two people. The cycles are not a forecast — they are the structural background the chart moves through.
FAQ
- Is this BaZi chart calculator free?
- Chart calculation is free within the daily chart allowance: guests can add 1 new chart, free signed-in accounts 2, and subscribers have unlimited chart access. The overview has a free preview; sign in to read its full text and the natal blueprint free, without credits. Other chapters have separate access conditions.
- What if I do not know my birth hours?
- You can still chart. The year, month and day pillar hold, and Day Master strength is still meaningful. Only the hour pillar and anything read from it are left out — we mark that on the chart rather than filling it in with a guess.
- Do you correct the birth time?
- The result shows the time convention used. Default charting can apply birthplace longitude correction; the advanced apparent-solar-time option also includes the equation of time. Even a small correction can cross an hour boundary, so check the entered time and selected convention near a boundary.
- Why does my chart differ from another site?
- Usually one of three things: where the year boundary is drawn (we use Li Chun, not January 1), how the late Zi hour between 23:00 and midnight is handled, or whether the birth time was longitude-corrected. All three are stated on the chart page.
For reflection and self-understanding. Nothing here is medical, legal or financial advice.