What is BaZi (the Four Pillars of Destiny)?

BaZi, or the Four Pillars of Destiny, is the core method of classical Chinese astrology. A person's birth year, month, day and hour are each expressed as a Heavenly Stem paired with an Earthly Branch — eight characters in total ("BaZi" = "eight characters"), arranged in four pillars ("Si Zhu"). The Day Stem is the Day Master, representing the person; the relationships (Ten Gods), hidden stems, melodic elements, symbolic stars, and luck pillars among the other characters form a complete system of analysis rooted in classics such as Zi Ping Zhen Quan and Di Tian Sui.

Are "Four Pillars", "birth eight characters" and "Zi Ping" the same thing?

Yes — they are different names for one tradition. "Four Pillars" stresses the year/month/day/hour structure, "birth eight characters" stresses the birth time as the source, and "Zi Ping" refers to the day-master-centred method established by Xu Ziping in the Song dynasty. Modern BaZi charting follows this Zi Ping orthodoxy, as does this tool.

What are the Ten Gods, and why are they central to BaZi?

The Ten Gods describe how every other stem and branch relates to the Day Master by the five-element cycle and yin/yang: Friend & Rob Wealth (same as self), Eating God & Hurting Officer (output), Direct & Indirect Wealth (what self controls), Direct Officer & Seven Killings (what controls self), Direct & Indirect Resource (what generates self). They translate abstract element relations into human meaning (wealth, authority, resource, expression) and drive structure, success and the choice of the favourable element.

How is the strength of the Day Master judged?

Strength depends mainly on whether the Day Master is supported by the month branch (the seasonal command), reinforced by stems and rooted in branches, balanced against what drains or controls it. A strong Day Master favours output, wealth and authority to balance it; a weak one favours resource and peers. The tool tallies element energy and Ten-God strength to help you judge.

What are hidden stems, and why list them?

Each Earthly Branch hides 1–3 Heavenly Stems (the "human element"), e.g. Yin hides Jia/Bing/Wu. Hidden stems carry primary, middle and residual qi and define a branch's true element and Ten-God content. The commanding hidden stem of the month branch is decisive for structure and the favourable element, so a professional chart always lists them.

What are the melodic (NaYin) elements?

NaYin assigns one of thirty melodic elements to each pair of the sixty Jia-Zi (e.g. Jia-Zi/Yi-Chou = "Gold in the Sea"). NaYin is used in compatibility, date selection and some schools' analysis, alongside the regular elements. The tool labels NaYin for all four pillars and the luck pillars.

Are the symbolic stars (ShenSha) reliable?

Symbolic stars are auxiliary markers — auspicious (Nobleman, Academic Star, Travelling Horse, Peach Blossom…) and inauspicious. The classical view treats structure and the Ten Gods as primary and stars as secondary: alone they are limited, but combined with structure and luck pillars they add nuance and warnings. The tool lists the mainstream stars by tier.

How are luck pillars arranged? What is the starting age?

Luck pillars derive from the month pillar, running forward or backward by the yin/yang of the year and the sex, each governing ten years. The starting age comes from the days between birth and the adjacent solar term divided by three. The tool determines the direction automatically, computes the exact start age, and links annual, monthly and daily luck.

What are the Life Palace, Body Palace and Fetal Origin?

The Life Palace (from month and hour branches) marks innate disposition; the Body Palace (from day and hour branches) marks lived experience; the Fetal Origin (derived from the month pillar) marks conception. With the four pillars they form the "seven pillars" used in advanced analysis — all generated automatically here.

What does "void" (KongWang) mean?

Within each ten-stem cycle two branches are left without a stem — these are the "void" branches of that day pillar. Forces falling on a void position are often reduced, to be re-weighed against clashes, combinations and "filling". The tool marks void branches from the day pillar's cycle head.

What is the chart structure (GeJu), and how is the favourable element chosen?

Structure is the core pattern, based on what the month branch's hidden stems reveal — normal structures (Officer, Killings, Wealth, Eating, Hurting, Resource) and special ones (Lu, Yang Blade, Follow, Transformation, Dominance…). The favourable element balances the chart through strength, climate and mediation. The tool applies Zi Ping Zhen Quan structure rules, Qiong Tong Bao Jian climate use and strength heuristics for a reference verdict.

What is the climatic favourable element (TiaoHou)?

Climate balances the chart by the season's cold/warm/dry/damp: winter births often need fire to warm, summer births water to moisten. Qiong Tong Bao Jian lists the climatic element for each "day stem + month" combination. The tool matches the relevant passage automatically.

Why correct to true solar time?

BaZi depends on an exact hour. China uses one standard time (120°E) but spans ~73°E–135°E, so local solar time can differ by over an hour. Near a pillar boundary — especially the Zi-hour day change at 23:00/01:00 — true-solar-time correction can change the hour or even day pillar. The tool offers longitude + equation-of-time correction in one click.

What is the difference between solar, lunar and eight-character input?

Three input modes are supported: solar (Gregorian) date is the most common; lunar date is converted to solar automatically, with leap months; and if you already know the four pillars you can enter them to reverse-look-up the date. All three produce the same chart — pick whichever you have.

Is this Four Pillars chart tool free? Do I need an account?

It is fully free with no sign-up: four pillars, Ten Gods, hidden stems, NaYin, symbolic stars, luck pillars, element strength, structure, climatic use and true-solar-time correction are open to everyone. Signing in adds cloud saving, cross-device sync and per-year notes.

Is online BaZi charting accurate?

Charting is deterministic astronomical/calendar computation: stems, hidden stems, NaYin, stars, luck-pillar start and the palaces are computed precisely and reliably. Note that charting is objective, while interpretation (verdicts, choice of favourable element) belongs to differing schools — the structure and favourable element shown here are for study only.

Can I save or share a chart?

Yes. After charting you can export JSON, generate a share link or save a poster image; signed-in users can store charts in the cloud, recall them from history and add per-year notes for long-term tracking.

BaZi Calculator · Four Pillars of Destiny

Free online BaZi chart — stems & branches, Ten Gods, hidden stems, NaYin, symbolic stars, luck pillars, element strength and structure

1918年12月16日 14:00大雪(1918.12.08)后8天14小时 · 距冬至6天Commanding Qi: 壬水(余气 · day 9/10)Luck starts: 7y 0m 10d(handover on 1925-12-26)

Structure: also（月令子中癸(七杀)为月令用事之神, 取七杀格）

Gender

Input mode

Four Pillars 四柱

Year

Month

Day

Hour

→ 1918-12-16 14:00

Four Pillars Chart

Show Conception / Life / Body palaces

	YearAncestry	MonthMonth Command	DayDay Master · Self	HourLater Life
Stem God	伤官Hurt Officer	正印Dir. Resource	男主	比肩Friend
Stem	戊	甲	丁	丁
Strength	囚	相	死	死
Branch	午	子	酉	未
Hidden	丁·火70% 己·土30%	癸·水100%	辛·金100%	己·土60% 丁·火30% 乙·木10%
Hidden God	比肩透食神	七杀	偏财	食神比肩透偏印
NaYin	天上火	海中金	山下火	天河水
Void	子丑	戌亥	辰巳	寅卯
Stage	临官	绝	长生	冠带
Seat	帝旺	沐浴	长生	冠带
Stars	禄神天厨将星桃花勾煞	灾煞绞煞	天乙贵人太极贵人文昌学堂将星十灵	羊刃红艳六厄寡宿
Branch	午子相冲 (Clash)·午未相合 (Combination)·子酉相破 (Destruction)·子未相害 (Harm)
Strength by month branch:水旺木相金休土囚火死

Relations:CombinationClashPunishmentHarmDestructionHover a stem or branch to see its relationsTap a stem or branch to see its relations

Percentages are this tool's hidden-stem weighting, not the live commanding-qi strength.

Advanced analysis (structure, favourable element, classical texts) is currently available in Chinese only.

Luck 1918–1924

Luck Pillars

Ten years to a pillar · the axis of a life

Tap a luck pillar for its years, a year for its months · tick to add to the chart

Luck · Annual Pillars

One pillar a year · the season in command

Energy distribution

Weighted Five Elements · Ten Gods

木

火

土

金

水

木

Wood

11%

火

Fire

28%

土

Earth

12%

金

Metal

16%

水

Water

33%

How are these numbers computed? (show the formula)

A two-layer weighted sum, then normalisation. Each heavenly stem contributes the full positional weight of its pillar; each branch splits its positional weight across its hidden stems (primary / middle / residual), and every part is mapped to an element and a Ten God before being summed.

score(element e) = Σ stems [ W_stem(pos) · 1(element = e) ] + Σ branches Σ hidden_k [ W_branch(pos) · R(count)[k] · 1(element = e) ] percent(e) = score(e) / Σ score

Positional weights W: year stem 6, month stem 12, day stem 12, hour stem 12; year branch 10, month branch 40, day branch 20, hour branch 10. The month branch dominates — it carries the seasonal command.
Hidden-stem split R: branches with three hidden stems use 0.6 / 0.3 / 0.1 (primary / middle / residual), two hidden stems use 0.7 / 0.3, a single hidden stem takes the full 1.0. Example — a 寅 month branch (hiding 甲丙戊) gives Wood +40×0.6=24, Fire +40×0.3=12, Earth +40×0.1=4.
Normalisation: each score is divided by the total to give a percentage. Cards show scores to one decimal and percentages rounded to integers, so the five percentages may not sum to exactly 100%.
Scope: the element bar includes the Day Master stem itself (weight 12) to show overall momentum; the Ten Gods bar excludes it (the Day Master has no Ten God relation to itself), so the two totals differ.

This chart applies only the two layers above — positional weight and hidden-stem split. It does not apply seasonal-phase coefficients (prosperous/strong/resting/trapped/dead), depth-of-command bonuses, or adjustments for punishments, clashes and combinations. Seasonal phases are shown in a separate row under the chart; clash/combination corrections apply only to the strength and Useful God verdicts, which use a different scoring basis and should not be cross-checked against these numbers.

格局详解

主格 · 判定链路 · 兼格

未透

正八格用神癸

月令子中癸(七杀)为月令用事之神, 取七杀格

判定链路 · 子平真诠

○ 化气格→○ 专旺格→○ 从旺/从强→○ 从格→○ 两神成象→○ 禄刃格→● 月令取用

依序尝试, 首个命中即为主格：● 命中 · ○ 不成立 · ─ 未检 (前序已命中)。悬停可见各步判定条件。

兼格 · 不与主格竞争

日柱格

日柱丁酉为日贵格之日, 兼取为格

用神喜忌

两派并参 · 喜忌分明

身弱

综合喜用

木土火

综合忌神

金水

格局派 ·《子平真诠》

逆用

七杀格

相神木

喜神火

忌神金

七杀格身弱, 杀重攻身: 以印化杀为相神, 比劫帮身为喜, 最忌财星党杀。

盲派 · 段氏做功

做功成立

功神时未土年午火

喜用土火

忌神木水

功神时未以子未穿取官杀做功, 直取官杀; 喜土、火助功神把功做实, 忌木、水破功。盲派不论身强弱, 唯以做功论喜忌。

格局派依《子平真诠》之成败救应 · 顺逆用神法立相神；盲派依段氏做功论命，以功神论喜忌、不论身强身弱。两派并参，综合喜用为两派之并集。

命局病药

病药论 ·《神峰通考》

病重药真

此局之病: 忌神秉令、用神木带伤; 对症之药: 火 (制忌)、土 (制忌)、木 (通关)。有病方为贵, 无伤不是奇 — 病重而药真, 去病之时非富则贵, 起伏大而格局亦大。早岁即得药运, 起步顺遂, 贵在乘势蓄根基。

命中之病

●●●
忌神秉令
月令子属水, 忌神当权得时, 一局气势先输一着, 全盘喜用皆须逆势做功。
●●●
用神木带伤
用神木之根未被子所穿 — 根摇则用神受损, 吉处藏凶, 最喜岁运解救。

对症之药

火制忌原局有力

克制忌神金, 直去其病。

原局有气, 岁运一引即可发力。

土制忌原局有力

克制忌神水, 直去其病。

原局有气, 岁运一引即可发力。

木通关原局微弱

泄忌神水之气而转生喜用, 化敌为友。

原局仅存微根, 药力薄, 须岁运补足。

药至应期 · 逐运

乙丑8-17岁药至乙丑药气入运而不带病, 病处得医之期
丙寅18-27岁药至丙寅药气入运而不带病, 病处得医之期
丁卯28-37岁药至丁卯药气入运而不带病, 病处得医之期
戊辰38-47岁药至戊辰药气入运而不带病, 病处得医之期
己巳48-57岁药至己巳药气入运而不带病, 病处得医之期
庚午58-67岁药至午截脚制庚, 病干无根, 药气仍行
辛未68-77岁药病相杂辛盖头压未中药气, 药力打折, 吉而有阻
壬申78-87岁病发忌神壬申会聚入运, 病处受激, 守成为要
癸酉88-97岁病发忌神癸酉会聚入运, 病处受激, 守成为要

What is BaZi (the Four Pillars)?

BaZi, the Four Pillars of Destiny, is the core method of classical Chinese astrology. A person's birth year, month, day and hour each form a "pillar" of one Heavenly Stem and one Earthly Branch — eight characters in total. The Day Stem is the Day Master, representing the person; the other seven characters interact with it through the five-element cycle to form a complete natal chart.

A professional Four Pillars chart shows not only the eight characters but also the Ten Gods, hidden stems, NaYin elements, voids, the twelve life stages, symbolic stars, luck pillars, element strength, the Life/Body Palaces and Fetal Origin, plus structure and climatic favourable elements. This tool computes all of them at once, supports solar, lunar and eight-character input with true-solar-time correction, and is free with no sign-up.

How to chart BaZi: four steps to your natal chart

Charting is deterministic calendar computation — these four steps let you read any BaZi chart.

1
① Fix the birth time
BaZi rests on an exact hour. For cross-region or boundary Zi-hour (23:00/01:00) births, correct longitude with true solar time first.
2
② Lay out the four pillars
Set the month pillar by the 24 solar terms and the hour stem from the day stem to get all eight characters.
3
③ Annotate the elements
List the Ten Gods, hidden stems, NaYin, voids, life stages and stars for each pillar, and tally element strength.
4
④ Luck pillars & favourable element
Arrange luck pillars by yin/yang direction, compute the start age, then judge the favourable element from structure and climate.

Every step above is automated here — enter your birth details and tap "Chart" to get the full result at once: pillars, Ten Gods, hidden stems, NaYin, stars, luck pillars, element strength and structure.

What a BaZi chart shows: the ten core elements

Understand these ten elements and the whole Four Pillars chart opens up.

Stems, Branches & the Four Pillars: Ten Heavenly Stems and twelve Earthly Branches pair into the sixty Jia-Zi. Year, month, day and hour each take one pair — the four pillars, the skeleton of the chart.
Day Master & the Ten Gods: The Day Stem is the Day Master. Measured against it, the other characters yield the Ten Gods (Friend, Rob Wealth, Eating God, Hurting Officer, Wealth, Officer, Killings, Resource…), which drive structure and analysis.
Hidden Stems: Each branch hides 1–3 stems (primary, middle, residual). The commanding stem of the month branch is decisive for structure and the favourable element.
NaYin Elements: Each pair of the sixty Jia-Zi carries a NaYin element (e.g. Gold in the Sea), thirty in all, used in compatibility, date selection and analysis.
Symbolic Stars (ShenSha): Auspicious stars (Nobleman, Academic, Travelling Horse, Peach Blossom…) and inauspicious ones add nuance and warnings alongside structure — treated as secondary in the classics.
Luck Pillars & Annual Luck: Luck pillars run from the month pillar, ten years each; the annual pillar interacts with the chart to shape each period. The tool links annual, monthly and daily luck.
Element Strength & Favourable Element: Judge the Day Master's strength from the season, roots and stems, then choose the favourable and unfavourable elements by strength, climate and mediation.
Chart Structure: The month branch defines normal and special structures (Officer, Killings, Wealth, Eating, Hurting, Resource, Lu, Yang Blade, Follow, Transformation…), whose success sets the chart's level.
Void & Life Stages: Voids (two stem-less branches from the day pillar's cycle) weaken forces that land on them; the twelve life stages (Birth, Bath … Peak … Tomb, Death) gauge a stem's state within a branch.
Life / Body Palace & Fetal Origin: The Life Palace (month + hour), Body Palace (day + hour) and Fetal Origin form the "seven pillars" with the four pillars — auxiliary coordinates for advanced reading.
True Solar Time: China uses one standard time (120°E) yet local solar time can differ by over an hour. Boundary Zi-hour births especially need true-solar-time correction.
Classical Sources: Structure follows Zi Ping Zhen Quan and climatic use follows Qiong Tong Bao Jian, with reference to Di Tian Sui, San Ming Tong Hui and Yuan Hai Zi Ping.

FAQ

Four Pillars (BaZi) Chart — FAQ

延伸阅读

名人命例与流年通览，都可一键回到排盘工具对照。

名人八字命例

帝王将相、文臣名士的四柱与十神，附生辰出处与可靠度。

2026 年流年运势 · 十日主分论

按日主看今年太岁十神：事业、财运、感情逐项解读。

Related charting tools

Beyond BaZi charting, these tools share the same Four Pillars roots.

True Solar Time

Longitude + equation-of-time correction — the essential step before BaZi charting.

Ganzhi Kaleidoscope

Stems & branches at a glance: sixty Jia-Zi, relation wheel, life-stage matrix, NaYin.