Free · No sign-up · Minute-accurate
Free BaZi calculator: your four pillars, decoded
Enter your birth date, time, and city. Get your complete BaZi chart — day master, five-element balance, hidden stems, ten gods and ten-year luck cycles — computed by a versioned astronomical calendar engine, not guesswork.
Engine v1.1.0
versioned, reproducible
4,000+ cases
cross-validated 1900–2100
Solar terms to the minute
true solar time built in
No account
nothing to sign up for
What’s free, what’s paid
The chart is free. The reading is optional.
Everything the engine can compute, you get for free — no account, no paywall, no “unlock”. The only thing you can pay for is the written reading: a report that costs us money to generate, and therefore has a price.
Free, forever — no sign-up
$0Computed by the engine. Every number is yours to keep.
- Full four-pillar chart — year, month, day, hour
- Day master & five-element balance
- Hidden stems, ten gods & Na Yin
- True solar time correction
- Luck pillars (大运) with a 100-year annual timeline
- Branch interactions — clash, combination, punishment, harm
- Share card — download your chart as an image
- The methodology behind every number
Life Map report
$5.99 onceWritten from your chart by AI, checked by a rule-based QA gate.
- 7-chapter Life Map (~2,500–3,500 words)
- Day master deep dive & element strategy
- Strengths, challenges & growth edges
- Career, wealth & relationship patterns
- Your current luck pillar and this year’s theme
- Delivered instantly — the link stays yours
No subscription. No account required.
How it works
From birth details to a chart you can check
Three steps, one of them optional. The first result is free and stays free — the engine never asks you to sign up to see your own chart.
Enter your birth details
Date, time (or “time unknown”), and city. The city sets your time zone and longitude automatically.
Get your Four Pillars chart
Four pillars, day master, five elements, hidden stems, ten gods — with the engine version and conventions shown, so the result stays auditable.
Go deeper (optional)
Unlock a 7-chapter Life Map report written from your chart, or explore the ten day masters.
Free tools
Look up one thing at a time
Each of these runs the same engine as the main calculator, needs three fields, and tells you on the page how the number was produced.
- Five elements calculatorWood, Fire, Earth, Metal, Water — counted from all eight characters.Open
- Day master calculatorThe one character your whole chart is read against. Date only.Open
- Ten gods calculatorEvery stem named by its relationship to your day master.Open
- Stems & branches (干支)Ten stems, twelve branches, sixty pairs, and the hidden stems.Open
- Luck pillars calculatorEight ten-year cycles from your month pillar — direction, 起运 age and a 100-year timeline.Open
- Compatibility calculatorTwo charts compared: day masters, element exchange, cross-chart interactions.Open
- Chinese zodiac compatibilityTwo signs, and the real branch relation behind the pairing — no star ratings.Open
- True solar time calculatorThe clock time correction — and whether it moves your hour pillar.Open
- Saju calculator (사주)The Four Pillars under their Korean name — same engine, same 입춘 boundary, Korea’s clock history handled.Open
The system
What is BaZi — the Four Pillars of Destiny?
BaZi (八字) is the classical Chinese system of destiny analysis, known in English as the Four Pillars of Destiny. Where Western astrology looks to the planets, BaZi looks to time itself: your birth year, month, day, and hour are each mapped to a pair of characters — one heavenly stem and one earthly branch — and those eight characters form your chart.
The chart is read through the day master, the stem of your day pillar, which stands for you. Every other character is then classified by its relationship to that stem: the ten gods describe how you engage with wealth, authority, creativity, and knowledge; the five elements — wood, fire, earth, metal, water — describe where your energy is abundant and where it runs thin.
Two things make or break a BaZi chart: the calendar and the clock. The year pillar does not change on January 1st — it changes at 立春, the exact moment of the Start of Spring, and months shift at each solar term, not on the first of the month. And because the sky does not follow time-zone borders, a precise chart corrects your birth time for true solar time. This calculator does both, with every convention published on the result.
The result is a Chinese astrology birth chart you can actually check: the same astronomical rules, applied deterministically, with the engine version shown. Use it for self-reflection and cultural exploration — or turn it into a full 7-chapter Life Map reading.
- 天干Heavenly Stems
- Ten stems (甲 Jiǎ to 癸 Guǐ) alternating yin and yang, each carrying one of the five elements. Your day stem is the day master — the core of the chart.
- 地支Earthly Branches
- Twelve branches (子 Zǐ to 亥 Hài) marking months, two-hour periods, and the zodiac animals. Each branch hides one or more stems with their own influence.
- 四柱Four Pillars
- One stem–branch pair each for the year, month, day, and hour of birth — eight characters in total, hence the name BaZi (八字, “eight characters”).
- 五行Five Elements
- Wood, fire, earth, metal, and water — not substances but phases of energy. Their balance across the eight characters describes your constitutional shape.
- 十神Ten Gods
- The relationship of every other stem to your day master: companion, wealth, officer, seal… Each labels a pattern of behaviour and circumstance.
- 节气Solar Terms
- The 24 astronomical markers of the Chinese calendar. The year pillar changes at 立春 (Start of Spring), months at each 节 — computed here to the minute.
Under the hood
Every chart states its own rules
BaZi sites disagree with each other — and usually with themselves — about which convention they follow. So we publish ours, on every result: the engine version, the calendar boundaries, the time basis. Same engine version, same input, same numbers. Always.
Engine v1.1.0 · lunar-javascript 1.7.7 calendar tables · 168/168 self-test cases green
- Year pillar
- changes at the exact moment of 立春
- Month pillar
- changes at each 节 (solar term), to the minute
- Day pillar
- changes at midnight
- Hour 23:00–23:59
- hour stem follows the next day’s stem
- Time basis
- true solar time — longitude + equation of time
- Luck pillars
- days to the nearest 节 ÷ 3; direction by year polarity & gender
Questions
Frequently asked questions
BaZi (八字, “eight characters”) is the Chinese astrological system also known as the Four Pillars of Destiny. Your birth date and time are mapped to four pairs of heavenly stems and earthly branches — one pair each for the year, month, day, and hour of your birth — forming a chart that describes your constitutional energies.
The chart is computed by a deterministic astronomical calendar engine, cross-validated on 4,000+ cases between 1900 and 2100. Solar terms are resolved to the minute, and your birth time is adjusted for true solar time using your city’s longitude.
Your birth time determines the hour pillar. If you do not know it, you can still get a three-pillar chart (year, month, day) — the day master, which anchors every reading, only needs the date. For the fullest picture, a time within about two hours is usually enough.
Clocks follow time-zone boundaries; the sky does not. True solar time corrects your birth time for your longitude and the equation of time — usually a difference of a few minutes, occasionally enough to change the hour pillar near a boundary. We apply it by default, and you can switch it off.
No. BaziPattern is for entertainment and cultural exploration. Readings describe patterns and tendencies — never fixed predictions — and they are not medical, legal, or financial advice.
Your birth data is used only to compute your chart and any report you order. We do not sell personal data or build advertising profiles. See our Privacy Policy for retention and deletion details.
Learn
Start with the fundamentals
Comparisons
BaZi vs Zi Wei Dou Shu: Two Maps, One Birth
One birth moment, two charts that share almost nothing: eight characters read off a solar-term calendar, or fourteen stars placed into twelve lunar palaces. What each one computes, and why the two can disagree about what year you were born in.
ReadFoundations
What Is Saju? The Korean Four Pillars, Explained
Saju is not a rival system that arrived at the same answers: it is the same Four Pillars, carried to Korea and renamed. Where it genuinely diverges is the history of Korea's clocks.
ReadComparisons
BaZi vs Western Astrology — Different Clocks, Different Claims
These are not two readings of the same data. Western astrology needs the sky; BaZi needs the calendar. That difference decides everything else — including which birth-time mistakes actually break a chart.
ReadNo sign-up · No paywall
Your chart is one minute away
Enter your birth details and read your four pillars — day master, five elements, hidden stems, ten gods and luck cycles. The full Life Map reading is $5.99, one time, only if you want it.
BaziPattern · entertainment and cultural exploration, not prediction