🔮 Four Pillars (Saju) Calculator

Enter your birth date and time to calculate your Four Pillars based on solar terms, along with the Five Elements, Ten Gods, and zodiac animal. Results are for entertainment and reference only.

Calendar Type

Solar Lunar

Year

Month

Day

Birth Time

12 Earthly Branches Time Chart

Branch (時)	Time
子 Rat hour (Zi)	23:00 ~ 00:59
丑 Ox hour (Chou)	01:00 ~ 02:59
寅 Tiger hour (Yin)	03:00 ~ 04:59
卯 Rabbit hour (Mao)	05:00 ~ 06:59
辰 Dragon hour (Chen)	07:00 ~ 08:59
巳 Snake hour (Si)	09:00 ~ 10:59
午 Horse hour (Wu)	11:00 ~ 12:59
未 Goat hour (Wei)	13:00 ~ 14:59
申 Monkey hour (Shen)	15:00 ~ 16:59
酉 Rooster hour (You)	17:00 ~ 18:59
戌 Dog hour (Xu)	19:00 ~ 20:59
亥 Pig hour (Hai)	21:00 ~ 22:59

Five Elements: Generating and Controlling Cycles

Generating cycle (相生, mutual nourishment)

Wood generates Fire (木生火): wood feeds fire
Fire generates Earth (火生土): fire and ash nourish earth
Earth generates Metal (土生金): earth holds metal
Metal generates Water (金生水): metal and minerals produce water
Water generates Wood (水生木): water nourishes wood

Controlling cycle (相剋, mutual restraint)

Wood controls Earth (木剋土): roots penetrate the soil
Earth controls Water (土剋水): earth blocks water
Water controls Fire (水剋火): water extinguishes fire
Fire controls Metal (火剋金): fire melts metal
Metal controls Wood (金剋木): metal cuts wood

GUIDE

Learn more

What Are the Four Pillars of Destiny?

The Four Pillars of Destiny, also called Saju Palja or Bazi (四柱八字), represent a person's birth year, month, day, and hour as four pillars and eight characters. Each pillar consists of one Heavenly Stem (天干), representing heavenly energy, and one Earthly Branch (地支), representing earthly energy. Four pillars therefore contain eight characters, which is why the system is called Bazi, or "eight characters." The ten Heavenly Stems are Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, and Gui, while the twelve Earthly Branches are Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, and Hai. Pairing them produces 60 combinations known as the sexagenary cycle, which repeats every 60 years. The most important character in a chart is the Day Stem (日干), or Day Master, the Heavenly Stem of the day you were born. It represents the self, and its relationships with the other seven characters are used to examine personality, wealth, relationships, health, and more. This calculator is designed to derive those eight characters accurately; in-depth interpretation is best left to a specialist.

Why Are Solar Terms Used Instead of Lunar Dates?

Contrary to a common misconception, the Year and Month Pillars are determined by solar terms (節氣), not by lunar-calendar dates. The Saju year begins at Start of Spring (立春), around February 4, rather than Lunar New Year. For example, someone born on February 1 still uses the previous year's stem-branch combination if Start of Spring has not yet occurred. Likewise, the Month Pillar changes at that month's solar-term boundary rather than on the first day of the month. Start of Spring begins the Tiger month (寅月), Awakening of Insects begins the Rabbit month (卯月), and Clear and Bright begins the Dragon month (辰月), with 12 solar terms marking the boundaries of the 12 months. This calculator uses astronomical calculations to find when the Sun's ecliptic longitude changes by each 15-degree interval, then determines the solar-term date in Korea Standard Time (KST). This is more accurate than simply fixing the boundary at February 4. However, if a solar term begins near midnight on your birth date, a one-day difference may change a pillar, so verification with a professional Four Pillars calendar is recommended.

The Day Pillar, Sexagenary Cycle, and Hour Pillar

The Day Pillar (日柱) is the stem-branch pair assigned to the day of birth. Regardless of whether a solar or lunar calendar is used, the 60 combinations advance by one each day. This calculator derives the Day Pillar using the Julian Day, a continuous day count, anchored to the cross-verified date January 1, 2000, which was a Wu-Wu (戊午) day according to multiple public Four Pillars calendars. This keeps the 60-day cycle aligned for every date. To derive the Hour Pillar (時柱), the birth time is divided into the two-hour periods of the 12 Earthly Branches, and the Hour Stem is assigned from the Day Stem using the Five Rats method (五鼠遁). For example, the Rat hour (子時) begins with Jia-Zi for someone born on a Jia (甲) or Ji (己) day. If the birth time is unknown, the Hour Pillar is omitted and only the other three pillars are shown. Note that the Rat hour from 23:00 to midnight overlaps the date boundary and is handled differently by different schools, so results for births during this period should be treated as a reference only.

Reading Balance Through the Five Elements and Ten Gods

Each of the eight characters belongs to one of the Five Elements: Wood (木), Fire (火), Earth (土), Metal (金), or Water (水). A Four Pillars reading first examines how evenly these five energies are distributed. An element that is overly abundant may express its qualities strongly, while a missing element may suggest less experience in the areas associated with it. The elements interact through two cycles. In the generating cycle, Wood generates Fire, Fire generates Earth, Earth generates Metal, Metal generates Water, and Water generates Wood. In the controlling cycle, Wood controls Earth, Earth controls Water, Water controls Fire, Fire controls Metal, and Metal controls Wood. The Ten Gods (十神) classify the elemental and yin-yang relationships between the Day Master and the other characters as Friend, Rob Wealth, Eating God, Hurting Officer, Indirect Wealth, Direct Wealth, Seven Killings, Direct Officer, Indirect Resource, and Direct Resource. Each symbolizes an area of life: Wealth relates to money, Officer to reputation and career, and Resource to wisdom and documents. This calculator provides a basic Ten Gods classification for the Heavenly Stem and principal hidden stem of each pillar.

Accuracy and Limitations of This Calculator

This tool was built with accurate stem-branch (干支) calculation as its top priority. The Day Pillar uses the Julian Day and the 60-day sexagenary cycle to remain aligned across all dates, while the Year and Month Pillars use calculated solar longitudes to determine the precise solar-term transitions rather than relying on fixed-date estimates. The results were checked against several public Four Pillars calendars during development. For example, May 15, 1990 matches a Geng-Wu year, Xin-Si month, and Geng-Chen day. The tool does have several limitations. First, solar-term times are approximated to the minute, so a one-day discrepancy may occur in the extremely rare case of a transition immediately before or after midnight. Second, birth time is mapped directly to the 12 Earthly Branches using clock time without adjusting for the birthplace's apparent solar time. Third, the tool calculates the Four Pillars, Five Elements, Ten Gods, and zodiac animal and provides only a general balance interpretation. It does not offer advanced analysis such as Luck Pillars, annual cycles, or favorable elements, nor does it make personal predictions of good or bad fortune. All interpretations are for entertainment and reference only; consult a specialist before making important decisions.

Frequently asked questions

Should a Four Pillars chart use my lunar birthday?

No. The Year and Month Pillars are determined by solar terms, not by lunar-calendar dates. The Saju year changes at Start of Spring, around February 4, and each month changes at its solar-term boundary. You may therefore enter either a solar or lunar date; lunar dates are converted internally to solar dates, and the chart is calculated using solar terms.

I was born near Start of Spring. Is my Year Pillar correct?

The exact moment of Start of Spring determines the Year Pillar. A birth before that moment uses the previous year's stem-branch combination, while a birth afterward uses the current year's combination. This calculator derives the transition time astronomically, but only to the nearest minute. If you were born on a boundary date in a year when Start of Spring occurred near midnight, we recommend checking your exact birth time with a professional Four Pillars calendar.

What if I do not know my birth time?

The Hour Pillar depends on your birth time, so it cannot be calculated without it. Select "Unknown" to omit the Hour Pillar and display the Year, Month, and Day Pillars with their corresponding Five Elements and Ten Gods. All other results will still be calculated normally.

How is the Day Pillar calculated?

The calculation uses the fact that the 60 stem-branch combinations advance by one each day. This calculator uses the Julian Day, a continuous day count, and aligns it with the verified reference date January 1, 2000, a Wu-Wu (戊午) day, to accurately calculate the Day Pillar for any date.

Can I trust these results?

The stem-branch combinations that make up the Eight Characters were cross-checked against public Four Pillars calendars for accuracy. However, the Five Elements and Ten Gods interpretation is a rule-based summary of general principles and is intended only for entertainment and reference. It does not cover advanced analysis such as Luck Pillars or favorable elements, or make personal predictions of good or bad fortune. Consult a specialist before making important decisions.