Free tool · No account needed
Free BaZi Calculator: Four Pillars Chart
This bazi chart calculator runs the same Four Pillars engine as our full readings: true solar time from the birth city, Ten Gods, five-element balance and luck pillars — computed in the browser, free of charge.
For entertainment purposes only. A BaZi chart is reflective cultural guidance rather than a prediction of fixed fate, and it is not medical, legal or financial advice.
How this bazi calculator works
Four Pillars (BaZi) is a calendar system: the year, month, day and hour of birth each carry a Heavenly Stem and an Earthly Branch. The calculator converts clock time to true solar time first, then reads the chart from it.
- Enter the birth date and hour. Use the local clock time written on the birth record — the hour decides the fourth pillar.
- Pick the birth city. The city supplies the exact coordinates the true solar time correction needs; clock time alone is not enough.
- Read the chart. Day Master, five-element balance, the Ten Gods of every pillar and the luck pillars appear at once, together with the corrections that were applied.
Why the birth city changes the chart (true solar time)
BaZi follows the sun rather than the clock. Turning clock time into true solar time takes two corrections, and both depend on where the birth happened.
- Longitude correction: the sun crosses one degree of longitude in four minutes, so a city far from the central meridian of its time zone can shift the hour by roughly half an hour.
- Equation of time: across the year the sun runs up to about sixteen minutes ahead of, or behind, the mean day.
- Together they can push the birth moment across an hour boundary — and a different hour pillar changes how that pillar reads.
- Across six leading BaZi sites we compared, three never ask for a birth place at all, so this correction can never be applied there.
If the birth hour is unknown
An hour pillar guessed from a default time is worse than no hour pillar at all. Choose the unknown-hour option and the chart is built from the year, month and day pillars: the Day Master and the five-element balance stay reliable, while hour-dependent details are marked as open rather than invented. The hour can be narrowed down afterwards through event-based rectification.
Narrow down the birth hour with AI rectificationBaZi calculator questions
Is this bazi calculator free?
Yes. The chart is calculated in the browser, with no sign-up, no payment and no limit on how many charts can be run.
Are the birth details stored?
No. The chart is computed on your device, so your birth date, hour and gender never reach us. The city search is the one lookup that does: we do not write the query to our application logs, and the public place data it returns is kept in an anonymous cache (Cloudflare's platform request logs are sampled at 1% and retained for up to 7 days) — no account, cookie or IP — so repeat searches stay fast.
What happens when the exact birth hour is unknown?
The chart is built from three pillars (year, month, day). Hour-dependent details are marked as open instead of being guessed from a default time.
How accurate is the true solar time correction?
It combines the birth city's coordinates, the time zone offset in effect on that date (daylight saving included) and the equation of time. The equation of time is an approximation, typically within about a minute of the astronomical value; overall precision then follows the city and the clock time you enter.
Is this the same engine as the paid readings?
Yes. The free tool and the paid reports share one Four Pillars engine, so the chart shown here is the chart a reading is written from.
Want the full reading of this chart?
The free chart shows the structure. A Mingsage reading interprets it chapter by chapter — Day Master, five elements, Ten Gods, luck pillars and the year ahead — written for that one chart.
Ordering takes about two minutes, no account needed; the report arrives as a PDF and stays available online.
For entertainment purposes only. A BaZi chart is reflective cultural guidance rather than a prediction of fixed fate, and it is not medical, legal or financial advice.