Birth chart 四柱 · Four Pillars
Each pillar represents the year, month, day or hour of birth. A pillar contains two characters: a Heavenly Stem above an Earthly Branch. The four complete pillars contain eight characters. Your natal chart is this arrangement at the moment of birth.
Heavenly Stems 天干
The upper character of a pillar. The ten stems are Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren and Gui.
Earthly Branches 地支
The lower character of a pillar. The twelve branches are Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai.
From left to right, this chart shows the hour, day, month and year pillars. When the birth time is unknown, the hour pillar is left blank. A year or month pillar may also remain unconfirmed on a solar-term boundary date because its value can depend on the birth time.
Saju year and month pillars do not simply change on January 1 or the first day of a lunar month. They use the start of spring and relevant solar-term boundaries, so they can differ from the year and month of an ordinary calendar.
Day Master 日干 · A reference for the chart
The Day Master is the Heavenly Stem in the day pillar. Traditional Saju uses it as the reference representing the self and examines how the other characters relate to it.
For example, a Jia-Zi (甲子) day pillar has Jia (甲) as its Day Master. Jia belongs to Wood. This is an illustrative character pair, not a calculation for a specific birth date.
A single Day Master does not establish your personality. Treat its descriptions as interpretations of traditional symbols.
Five Elements 五行 · Five classifications
The Five Elements are Wood (木), Fire (火), Earth (土), Metal (金) and Water (水). Stems and branches are classified into these groups. The element chart counts each displayed stem and branch once.
A complete chart contains eight counted characters. The hour pillar is excluded if the time is unknown; unconfirmed pillars at solar-term boundaries are also excluded. Hidden Stems are not added separately, and no seasonal weighting is applied. Check the number of counted characters shown with your result.
Character counts are different from strength. A higher count does not necessarily mean an element is stronger. Traditional strength assessments also consider the season and relationships between characters. These counts do not determine Day Master strength, financial outcomes or relationship prospects.
Ten Gods 十星 · Relationships to the Day Master
These are ten names for how other characters relate to the Day Master through their element and yin or yang quality. They are also called the Ten Deities. The result explains which character was used to calculate each relationship.
Peer · Rival
The same element as the Day Master. Traditionally called Friend and Rob Wealth.
Creative output · Independent expression
The element produced by the Day Master. Traditionally called Eating God and Hurting Officer.
Flexible resources · Steady resources
The element controlled by the Day Master. Traditionally called Indirect Wealth and Direct Wealth.
Challenging authority · Structured authority
The element that controls the Day Master. Traditionally called Seven Killings and Direct Officer.
Independent learning · Supportive learning
The element that produces the Day Master. Traditionally called Indirect Resource and Direct Resource.
Each relationship is divided into two names according to the yin or yang pairing. These are symbolic labels: having Wealth does not establish that a person is rich, and lacking an Officer does not establish a poor relationship.
Combinations and clashes 合 · 沖
These traditional names describe specific pairs or groups of stems and branches. A combination symbolically suggests connection; a clash symbolically suggests opposing tendencies.
The reading checks whether the relevant pattern appears in your chart and adds an explanation when it does. A combination does not guarantee a favourable event, and a clash does not establish misfortune. Detecting a pair or group is distinct from judging its effects or a transformation into another element.
Time basis · KST and the 30-minute convention
This calculator uses Korean Standard Time (KST, UTC+9). For a birth outside Korea, first convert the solar birth date and time to KST, including any change of date, and enter it using the Solar option. The app does not automatically convert birth locations, longitude or world time zones.
You can choose “Korea convention · subtract 30 minutes” or “As entered (KST)”. The first subtracts 30 minutes from the KST time you enter. Use “As entered (KST)” to omit that optional adjustment.
The 30-minute adjustment is a simplified convention intended to account for a difference between Korean standard time and solar time. It is not a precise apparent-solar-time calculation using the birth location’s longitude and the date’s equation of time. An adjustment that crosses a date or hour boundary can change part of the chart.
No hour pillar is calculated when the birth time is unknown. The three-part 2026 Tojeong code does not use the birth time.
Tojeong Upper · Middle · Lower
A Tojeong code consists of three numbers: an upper part from 1 to 8, a middle part from 1 to 6 and a lower part from 1 to 3. There are 144 combinations. “Upper”, “middle” and “lower” name the parts of the code; they are not grades of fortune.
Upper · The first number
Add the traditional counting age for the selected year to the year-table value, then take the remainder after division by 8. A remainder of zero is shown as 8.
Middle · The second number
Add the length of the lunar birth month in the selected year to the month-table value, then take the remainder after division by 6. A remainder of zero is shown as 6.
Lower · The third number
Add the lunar birthday’s day number to the day-table value for that birthday in the selected year, then take the remainder after division by 3. A remainder of zero is shown as 3.
The year, month and day table values correspond to their stem-branch calendar pairs. The 2026 page calculates a code for 2026 and shows the details. The natal chart’s element counts are not used to select a Tojeong code.
A chosen calendar convention may affect leap months or lunar dates absent from the selected year. The calculation details show the date actually used.
Calculating the code and interpreting a historical text are different tasks. Our original Saju commentary is not presented as a translation of the 144 traditional texts. Monthly reflection questions are not monthly predictions of good or bad fortune.
How to read the seven areas of interpretation
Explore Personality, Business, Money, Relationships, Career & teamwork, Learning & growth, and Everyday rhythm. The library contains 10,140 base patterns in Korean and 10,140 in English, built around the 60 day pillars. It combines those patterns with explanations selected from your chart’s stem-based Ten Gods, element composition, and combinations or clashes.
These numbers count prepared base text patterns. They do not count all possible natal charts or mean that one pattern explains an entire life. The content is selected from static data and rules included in the app, without a separate database.
Keep calculated calendar characters distinct from symbolic interpretations. Expand the explanation of why a reading appears to see its day-pillar, Ten Gods, element or combination-and-clash basis. Unconfirmed pillars are excluded from conditions that require them.
Simple element counts do not establish Day Master strength, a favourable element, or outcomes in business, money or relationships. These readings do not include a comprehensive major-cycle assessment or predict particular events. Original 2026 Saju commentary is also kept distinct from the Tojeong code calculation.
For background, see the Encyclopedia of Korean Culture article on Saju and its article on Tojeong (both in Korean).
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