Free · true solar time · no sign-up
Free BaZi Calculator
Enter your birth date, time, and place. Your Four Pillars chart is calculated from true solar time — where the sun actually stood, not just what the clock said — and shown instantly, no account needed.
Why true solar time changes your chart.
Most free calculators feed your wall-clock time straight into the calendar. But your birth certificate records administrative time, not the sun. Three corrections separate the two — and an hour pillar, sometimes a day pillar, can flip on them.
Longitude correction
Your timezone's clock is set for one meridian; your birthplace almost never sits on it. Four minutes of solar time per degree of longitude — in wide timezones this alone exceeds an hour.
Equation of time
The sun runs up to ±16 minutes fast or slow across the year. A fixed offset can't capture it; the almanac correction for your birth date can.
Daylight saving time
DST moves the clock, not the sun. We resolve your birthplace's actual UTC offset for that exact date — including southern-hemisphere summers — instead of assuming the standard meridian.
And when a birth time falls inside a DST spring-forward gap — a clock reading that never physically existed — the calculator says so and declines to guess, rather than silently producing a confident wrong chart.
Tested where calculators usually break.
These are the boundary cases BaZi communities use to check any calculator: the Li Chun year boundary, the late Zi hour, daylight saving in both hemispheres, and the DST gap. Our engine's output on each, cross-checked against an independent implementation:
| Birth data | What it tests | Result (year · month · day · hour) |
|---|---|---|
| Beijing, Feb 4 1988, 20:00 | Li Chun boundary (before) | 丁卯 癸丑 己丑 甲戌 |
| Beijing, Feb 4 1988, 23:30 | Li Chun + late Zi hour | 戊辰 甲寅 庚寅 丙子 |
| New York, Jul 4 1985, 14:00 | US daylight saving time | 乙丑 壬午 甲辰 辛未 |
| Sydney, Jan 15 1995, 10:00 | Southern-hemisphere DST | 甲戌 丁丑 丙午 壬辰 |
| New York, Apr 28 1985, 02:30 | DST gap (clock time never existed) | flagged, no silent guess |
What the free chart includes.
- All four pillars with heavenly stems and earthly branches
- Your Day Master — element and polarity, the anchor of any reading
- Hidden stems, ten gods, Na Yin, and element balance
- Ten-year luck cycles (Da Yun) calculated from your birth data
The chart is instant and needs no account. During launch, the full nine-chapter written reading is also free — it takes a Google sign-in, with up to three reports per account.
Is this BaZi calculator really free?
Yes. The chart is free with no account. During the launch period the full nine-chapter reading is also free after a Google sign-in, limited to three reports per account.
What if I don't know my exact birth time?
You can still calculate: the chart is built from a noon assumption and clearly marked as partial precision. Year, month, and day pillars remain exact; the hour pillar is the one that needs a real time.
Why does this chart differ from other calculators?
Almost always true solar time. Calculators that skip the longitude correction, the equation of time, or DST resolution can land in a different hour — occasionally a different day or year. The boundary tests above show how we handle those edges.
Is my birth data shared or sold?
No. Birth details are used to calculate your chart and report. See the privacy policy for exactly what is stored and how to remove it.
Your eight characters are already fixed. See them.
Same birth moment, same chart, every time — the calculator just does the arithmetic honestly.