Free BaZi Calculator with AI Analysis (Four Pillars of Destiny)
What is BaZi (八字)?
BaZi — also called "Four Pillars of Destiny" (四柱命理) — is a Chinese astrology system over 1,400 years old that maps your birth moment into eight characters: two for the year, two for the month, two for the day, and two for the hour. Each pair carries one Heavenly Stem (天干) and one Earthly Branch (地支), and together they encode the energetic blueprint of your life.
Unlike Western astrology, BaZi is not based on planetary positions. It uses the solar calendar combined with the 24 jiéqì (节气) — astronomical solar terms that mark the precise transitions of qi throughout the year. Your BaZi chart reveals:
- Your Day Master (日主) — the stem on your day pillar that represents your core self.
- The Ten Gods (十神) — symbolic relationships between your Day Master and the other stems, mapping career, wealth, relationships, and obstacles.
- The Five Elements balance (五行) — Wood, Fire, Earth, Metal, Water — where you have abundance, where you have lack.
- Your Useful God (用神) — the element your chart most needs to thrive.
How is your BaZi calculated?
Most online BaZi calculators get one critical thing wrong: the timezone. They read your birth time as if it were Beijing local — which is wrong for anyone born outside China. We solve this with a split-call algorithm:
1. Year and Month pillars are calculated using the astronomically correct UTC instant — these depend on solar terms (jiéqì), which fire at the same instant globally. 2. Day and Hour pillars are calculated using your local birth clock — because classical doctrine derives these from where you actually were when you were born. 3. True Solar Time correction is applied based on your birth city's longitude — your local mean time is not the same as solar time. 4. The early Zi hour rule (早子時, 23:00–23:59) advances the day pillar to the next day, as classical texts prescribe.
Without this discipline, the Hour pillar is wrong for ~95% of users born outside Beijing, which throws off Ten Gods analysis, DaYun (10-year cycles), and every interpretation downstream.
How to read your BaZi chart, step by step
1. Find your Day Master
Look at the Day Pillar in your chart — specifically the top character (the Heavenly Stem). That's your Day Master. There are 10 possible Day Masters:
| Stem (Chinese) | Day Master | Element + Polarity |
|---|---|---|
| 甲 | Yang Wood | Tall pine — leadership, vision |
| 乙 | Yin Wood | Vine — adaptable, persistent |
| 丙 | Yang Fire | Sun — radiant, generous |
| 丁 | Yin Fire | Candle — focused, intimate |
| 戊 | Yang Earth | Mountain — stable, patient |
| 己 | Yin Earth | Garden soil — nurturing, accumulating |
| 庚 | Yang Metal | Sword — decisive, sharp |
| 辛 | Yin Metal | Jewelry — refined, precise |
| 壬 | Yang Water | Ocean — strategic, deep |
| 癸 | Yin Water | Rain — gentle, intuitive |
2. Read the Ten Gods (十神) on each pillar
The other characters in your chart are not "you" — they are forces acting on your Day Master. The Ten Gods classify them:
- Companion (比肩) + Rob Wealth (劫财) — peers, competitors, friends.
- Eating God (食神) + Hurting Officer (伤官) — your output: creativity, communication, products.
- Direct Wealth (正财) + Indirect Wealth (偏财) — money, partners (for men), what you control.
- Direct Officer (正官) + 7 Killings (七杀) — discipline, authority, pressure.
- Direct Resource (正印) + Indirect Resource (偏印) — knowledge, mentors, what supports you.
3. Map the Five Elements
Count how many characters in your chart belong to each element. A balanced chart distributes ~2 elements per type (8 characters / 5 elements ≈ 1.6 each). Severe imbalances are diagnostic:
- Wood-heavy → ambitious but rigid, prone to anger when blocked.
- Fire-heavy → charismatic but burns out, needs Water to cool.
- Earth-heavy → reliable but slow to move, needs Wood to grow.
- Metal-heavy → precise but cold, needs Fire to soften.
- Water-heavy → intuitive but ungrounded, needs Earth to contain.
4. Look at your DaYun (大運)
DaYun is the 10-year cycle that overlays your natal chart starting at a specific age (calculated from your birth + nearest jiéqì + gender). Each DaYun period emphasizes different elements and gods, opening or closing windows for career, wealth, marriage, and creativity. Your natal chart is the seed; DaYun is the season.
Why BaZi vs Western astrology?
Western astrology asks "what was the sky like when you were born?" — planet positions, sign overlays, house cusps. BaZi asks "what was the qi like at your birth moment?" — distilled into 8 characters that are computationally exact.
| Aspect | BaZi | Western Astrology |
|---|---|---|
| Calendar base | Solar (24 jiéqì) | Tropical zodiac |
| Output complexity | 8 characters, deterministic | 12 houses × 10 planets, interpretive |
| Time precision needed | Hour level (4-hour blocks) | Minute level for accurate houses |
| Cycles tracked | 10-year DaYun + annual + monthly | Transits, progressions, returns |
| Used for | Career, wealth, relationships, timing | Personality, life themes, transits |
Frequently Asked Questions
How accurate is your BaZi calculator?
We use the same astronomical jiéqì tables that classical Chinese almanacs use, with the split-call timezone fix described above. Our chart matches what a master would calculate by hand — verified against the kinqimen reference implementation and against multiple practitioner-validated test cases. If your hour is unknown, we still produce Year/Month/Day pillars correctly; only the Hour pillar requires the exact birth time.
What if I don't know my exact birth time?
Check the box "I don't know my hour" and we'll compute Year + Month + Day pillars only (75% of the analysis). For relationship compatibility, career timing, and DaYun start age, you really do need the hour — try asking a parent or checking your birth certificate.
Do you use AI to calculate the chart?
No. The chart calculation is 100% deterministic, written in Go using classical algorithms. AI is only used for interpretation of the calculated chart — and the AI is constrained to cite the actual chart data, not invent palace assignments. We've documented several cases where competitor AI tools hallucinate stars or doors that don't exist; our citation guard prevents that.
Is this free?
The calculator is fully free, no signup required. The AI interpretation of your full chart (Day Master, Ten Gods, Five Elements, Useful God, DaYun forecast) requires a free signup — no credit card. Premium ($9.99/mo) unlocks unlimited AI chat, chart history, and date selection tools.
Can BaZi predict the future?
BaZi describes the patterns and cycles in your life — not specific events. A "good year for wealth" is a window of opportunity, not a guarantee of money. Your decisions and effort still matter; BaZi tells you which decisions the qi favors at which moment.
What's the difference between BaZi and the 12 Chinese animal years?
The animal year is just one of eight characters in your BaZi chart (the bottom character of your year pillar). Reading only your animal is like reading only your sun sign in Western astrology — it's the entry point, not the full picture. Your BaZi adds the seven other characters that make you actually you.
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