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MUN · CALCULATOR

Free Saju Calculator

Enter your birth date, exact time if known, and birthplace to calculate your Four Pillars/Bazi chart — Heavenly Stems, Earthly Branches, and Five Elements. Free, no sign-up.

Birth Time

Calculation assumptions and limits

  • Solar and lunar inputs are distinct; lunar leap-month status must be supplied correctly.
  • Place correction uses the historical IANA UTC offset, daylight saving, and longitude to calculate local mean time (LMT), not apparent solar time with the equation of time.
  • If birth time is unknown, the Hour Pillar is omitted; no life-event inference can recover a verified historical clock time.
  • The output is a deterministic chart structure under these rules. Traditional interpretations are not scientifically validated predictions.
MUN · GUIDE

Understanding the Four Pillars (四柱)

How to calculate your Saju chart

Choose a solar or lunar birth date, enter the exact birth time if you know it, and select the birthplace. The free calculator returns the Year, Month, Day, and Hour Pillars with their Heavenly Stems, Earthly Branches, and Five Element counts. If the birth time is unknown, it leaves out the Hour Pillar instead of inventing one. No account is required.

What is Saju (四柱)?

Saju, literally "Four Pillars," is an East Asian system that organizes a birth moment into four columns — year, month, day, and hour. Each pillar holds two characters, so a complete chart (명식) is eight characters, which is why the same structure is called Bazi ("Eight Characters") in Chinese. The pillars follow traditional sexagenary-calendar rules, including solar-term boundaries; a lunar date is converted before the chart is calculated.

Heavenly Stems and Earthly Branches

Each pillar pairs one of the 10 Heavenly Stems (天干) with one of the 12 Earthly Branches (地支). The stems cycle through the five elements in yin and yang form, while the twelve branches correspond to the familiar zodiac animals. Together the stem–branch cycle repeats every 60 combinations, the classical sexagenary cycle used to label years, months, days, and hours.

The Five Elements (五行)

Every stem and branch maps to one of the Five Elements (五行) — Wood, Fire, Earth, Metal, and Water. A Saju chart is often summarized by counting how many of each element appear across its eight characters. This elemental breakdown is a structural description of the chart, not a prediction.

The Hour Pillar and birthplace time correction

The Hour Pillar depends on the birth time and can change near a two-hour boundary. This calculator uses the historical IANA time-zone offset, daylight saving, and the birthplace longitude to calculate local mean time (LMT). It does not add the equation-of-time correction required for apparent solar time, so it should not be described as a full true-solar-time calculation.

RELATED GUIDES

Understand your Saju chart

Use these guides to understand what the calculator returns and why birth time changes the Hour Pillar.

What is Saju? Korean Four Pillars explainedWhat the Year, Month, Day, and Hour pillars meanHeavenly Stems and Earthly BranchesFive elements calculator: find your element and its balance
MUN · FAQ

FAQ

Is the Saju calculator free?
Yes. Calculating your Four Pillars chart (명식) — the Heavenly Stems, Earthly Branches, and Five Elements — is completely free and requires no sign-up. Only the interpretation of the chart is a paid feature.
What if I don't know my birth time?
You can still generate the Year, Month, and Day Pillars. Only the Hour Pillar (時柱) requires a birth time; without it, the calculator leaves that pillar out rather than estimating a historical clock time.
What is Manseryeok (만세력)?
Manseryeok is a traditional calendrical reference used to map dates and times to their stem–branch (干支) values. This calculator applies those calendrical rules, including solar-term boundaries, to determine the four pillars.
How does birthplace time correction work?
The calculator uses the historical IANA time-zone offset, daylight saving, and longitude to calculate local mean time (LMT). Births near a two-hour boundary can receive a different Hour Pillar. The calculation does not include the equation of time used for apparent solar time.
What are the Four Pillars (四柱)?
The Four Pillars are the year, month, day, and hour columns of a birth chart. Each pillar has one Heavenly Stem and one Earthly Branch, giving eight characters total — the structural basis of Saju.
Are Saju, Four Pillars, and Bazi the same?
They refer to the same four-pillar, eight-character chart structure. Saju is the Korean name, Four Pillars is the common English name, and Bazi is the Chinese term for the eight characters.