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 pillar is the one most people come looking for. Its stem sets the Day Master; its branch decides which of the twelve two-hour periods the hour pillar can fall into. That is why this calculator asks for hours as well as a date — without an hour there is no hour pillar, and roughly a quarter of the chart is simply not there.
Each branch also hides one to three stems. Those hidden stems are where most of the chart actually lives: they carry the Ten God relations that describe how you relate to work, money, family and authority, and they are why two people born on the same day can read very differently.
Everything here is computed, not written. No score is invented, nothing is graded from 0 to 100, and the rules this calculator uses are stated so you can reconcile the chart against another one.
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?
- Yes — the calculator is free, needs no account, and has no daily limit. Paid reports are separate long-form writing built on the same chart; they never change the chart itself.
- 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?
- Only for longitude, and only when it matters. If the birth place sits far from the standard meridian of its time zone, we chart from the local mean time of that place; otherwise we use the civil clock time as given. Small equation-of-time adjustments are not applied — they never cross an hour-pillar boundary, so they add precision that is not real.
- 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.