Free online tool

Free BaZi Calculator — Four Pillars of Destiny

Four pillars of year, month, day and hour, with hidden stems, Five Element strength, Ten Gods, a useful-god suggestion and the luck pillars. The month pillar is derived from solar terms, not from the lunar first day. No sign-up required.

What BaZi is

Four Pillars of Destiny (Chinese: 八字, BaZi — literally “eight characters”) reads a life from the moment of birth. Each of the four pillars — year, month, day and hour — carries one Heavenly Stem and one Earthly Branch. Four pairs make eight characters, hence the name.

PillarStemBranchUsually read for
YearYear stemYear branchAncestry, origins, early childhood
MonthMonth stemMonth branchParents, siblings, formative environment — this pillar decides elemental strength
DayDay Master — the person themselvesDay branchThe self and marriage
HourHour stemHour branchChildren, later life

Unlike Zi Wei Dou Shu, which places stars into twelve palaces, BaZi uses no stars at all. Everything is read from the productive and controlling relations among the Five Elements, with the Day Master as the anchor.

Both relations fit into a single diagram. Grasp it and you hold the core of BaZi — the same diagram also serves Feng Shui, date selection and the I Ching:

Wood plants Fire fire Earth soil Metal metal Water water GENERATING Wood feeds Fire · Fire feeds Earth Earth feeds Metal · Metal feeds Water Water feeds Wood CONTROLLING Metal cuts Wood · Wood parts Earth Earth dams Water · Water quenches Fire Fire melts Metal LEGEND Generating — outer ring, they nourish each other Controlling — inner star, they restrain each other

The diagram is wide — on a phone, swipe sideways to see all of it.

Why the month pillar follows solar terms

This is where hand calculation goes wrong most often. The month pillar changes at a solar term, not on the first day of a lunar month — the Tiger month begins at Li Chun (start of spring), the Rabbit month at Jing Zhe, and so on.

Someone born within a few hours of a solar term boundary gets an entirely different month pillar, which then shifts the whole strength analysis and the useful god. The calculator derives solar-term moments from astronomical data, so there is no table to look up.

What the chart gives you

  • The eight characters — four stems, four branches, plus the hidden stems inside each branch.
  • Five Element strength — the weight of Metal, Wood, Water, Fire and Earth across the whole chart.
  • Ten Gods — how each stem relates to the Day Master: Direct Officer, Seven Killings, Direct Resource, Indirect Resource, Friend, Rob Wealth, Eating God, Hurting Officer, Direct Wealth, Indirect Wealth.
  • Useful god suggestion — the element to reinforce in order to balance the chart.
  • Luck pillars — ten-year cycles, running forward or backward depending on the year stem and gender.

An honest note

The calculation itself — pillars, hidden stems, solar terms, luck cycles — follows classical rules and is deterministic. The interpretation is offered as a cultural reference in the East Asian tradition. It is not advice about your health, finances or legal affairs, and it does not replace your own judgement.

Read more

Related tools: Zi Wei Dou Shu · I Ching · Chinese almanac · Feng shui · Qi Zheng Si Yu · Qi Men Dun Jia · Name analysis · Wedding date · Building year · Feng shui ruler · Da Liu Ren

Frequently asked questions

Are BaZi and Four Pillars the same thing?
Yes. “Four Pillars” refers to the pillars of year, month, day and hour; each pillar holds one Heavenly Stem and one Earthly Branch, so together they form eight characters — BaZi.
How is BaZi different from Zi Wei Dou Shu?
Zi Wei Dou Shu arranges stars across twelve palaces, each palace covering an area of life. BaZi uses no stars; it reads the productive and controlling cycles among the Five Elements, anchored on the Day Master. The two systems complement each other and many practitioners consult both.
Why does the month pillar not follow the lunar calendar?
Because the month pillar changes at a solar term. The Tiger month starts at Li Chun, not at the lunar new month. A birth close to a solar-term boundary can easily be assigned the wrong month pillar if the lunar calendar is used instead.
What happens if I was born at 11 p.m.?
This school follows the convention that the Zi hour rolls the date forward: from 23:00 the date is already the next day, while 00:00–01:00 keeps the current date. It is the single most common mistake in manual calculation.
Can I still get a chart without my birth hour?
You will get three pillars — year, month and day — but not the hour pillar. Much can still be read, though you lose a quarter of the information and the readings about children and later life become unreliable.
Is the tool free? Do I need an account?
It is free and no account is needed. An account (also free) is only required if you want to save charts, compare several charts or use the AI assistant.
Ask someone who knows

Experts of the Academy

Finished the chart and still unsure about something? Book directly with an expert of the Academy — BaZi and other systems. Consultations are currently held in Vietnamese. Consultations are currently held in Vietnamese.

Chang Đất

Chang Đất

Lecturer - Zi Wei Dou Shu Research and Consulting Expert
5.0(1)
Zi Wei Dou ShuTarotPythagorean Numerology
Sơn Chu

Sơn Chu

Founder & Chairman of SonChu Academy
No reviews yet
Feng ShuiI ChingZi Wei Dou Shu
Hoàng Đình Kì

Hoàng Đình Kì

Deputy Head of the Northern Zi Wei Dou Shu Club · Research & Consulting Committee of SonChu Academy
No reviews yet
Zi Wei Dou ShuI ChingEsoteric Studies Training
Dương Hoàng Hân

Dương Hoàng Hân

Deputy Head of the Northern Zi Wei Dou Shu Club, Research & Consulting Committee of SonChu Academy
No reviews yet
Zi Wei Dou ShuPhysiognomyI Ching
Want to study BaZi properly, or need someone to read for you? Leave your name and phone number — no need to pick a course or a teacher. The Academy will get back to you. (Lessons and consultations are in Vietnamese.)