Four Pillars of Destiny (BaZi)
What Is BaZi (Four Pillars of Destiny)? Reading Your Chart from Birth Data
Four Pillars of Destiny — BaZi in Chinese — converts your year, month, day and hour of birth into four sexagenary (stem-and-branch) pairs, then reads your fate from how those four pillars relate to one another. It was systematised in China's Song dynasty and reached Japan during the Edo period. Because it packs in more information than most other Eastern traditions, it is sometimes called "the king of fortune-telling."
What the four pillars are
The "four pillars" are the Year, Month, Day and Hour Pillars. Each is expressed as a pairing of one of the 10 Heavenly Stems (Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, Gui) with one of the 12 Earthly Branches (Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, Pig). There are 60 possible stem-branch combinations, known as the sexagenary cycle.
Each pillar governs a different stretch of your life. The Year Pillar reflects your ancestry, early childhood, and your standing in society. The Month Pillar covers your parents, career, and your years from youth into adulthood. The Day Pillar is your own essential nature, and also shows your relationship with a partner. The Hour Pillar speaks to children, subordinates, and your later years.
The Day Master sits at the centre of the chart
The single most important element in BaZi is the stem of your Day Pillar, called your Day Master. It stands in for you, and the entire chart is read from the viewpoint of how every other stem and branch relates back to it.
A Day Master of Jia, for instance, grows straight and tall like a great tree — direct, unbending, and unwilling to abandon a path once chosen. Yi, though also Wood, is more like a flowering plant: supple, and skilled at adapting its shape to whatever environment it finds itself in. Each of the ten stems carries its own distinct nature, and that nature is the foundation of your personality reading.
Reading the Five Element balance
Every stem and branch belongs to one of the Five Elements: Wood, Fire, Earth, Metal or Water. With four stems and four branches, a full chart has eight elements in total — known as the "Eight Characters." Counting how many of each element appear reveals where your temperament runs strong or thin.
The Five Elements interact through two cycles: generation (Wood feeds Fire, Fire feeds Earth, Earth feeds Metal, Metal feeds Water, Water feeds Wood) and control (Wood parts Earth, Earth dams Water, Water douses Fire, Fire melts Metal, Metal cuts Wood). The idea that you can compensate for an element you're short on through colour, objects, or direction is exactly what underlies this tradition's lucky colours and lucky directions.
The Ten Gods reveal today's fortune
The name given to the relationship between your Day Master and any other stem is one of the Ten Gods: Companion, Rob Wealth, Eating God, Hurting Officer, Indirect Wealth, Direct Wealth, Seven Killings, Direct Officer, Indirect Resource, and Direct Resource.
On a day when today's stem forms an Eating God relationship with your Day Master, for example, eating, talking and enjoying yourself are all favoured, and generosity toward others tends to be repaid twofold. A Seven Killings day, by contrast, tends to bring pressure — it favours letting time work in your favour rather than forcing a confrontation. This site combines that day's Ten God relationship with branch compatibility to calculate your score for the day.
How this site calculates it
The Year Pillar is calculated on a 60-year cycle from 1924 as its Jiazi base year, with the boundary between years set at the Start of Spring (around February 4th) rather than January 1st — so anyone born before roughly that date is calculated under the previous year's pillar. The Month Pillar uses the "Five Tigers" method to derive the month stem from the year stem; because the exact solar-term boundary is approximated by a representative day for each month, results for birthdays within a day or so of a solar term may drift slightly from a strict astronomical calendar.
The Day Pillar is found by counting elapsed days from January 1st, 1924 (set as a Jiazi day). The Hour Pillar assigns your birth time to one of the twelve two-hour branches and derives the hour stem from the day stem. When birth time is unknown, the Day Pillar's own branch is used as a stand-in for the Hour Pillar's branch.
* This article introduces the ideas behind this divination tradition and makes no claim to scientific validity. Please enjoy your reading as entertainment.