About K-Fortune and the Calculation Rules
K-Fortune uses fixed rules based on traditional Korean saju interpretation. The same inputs, target date and rules produce the same result. Scores and explanations are derived from relationships between the natal chart and the selected cycle.
How to use the free readings
- All saju readings, daily fortunes, Tojeong readings, compatibility and calendar tools are free, including scores and detailed explanations. No account or payment is required.
- Enter your birth date and time for daily, monthly, annual or lifetime readings. You can select a two-hour birth period or choose Time unknown.
Building the natal chart
- The year pillar changes at Beginning of Spring and the month pillar at its solar-term entry time. Solar terms use astronomical calculations based on VSOP87.
- The day pillar follows the 60-day cycle. The hour pillar uses mean solar time at 127.5° E, equivalent to modern Korean standard time minus 30 minutes.
- Under modern Korean standard time (UTC+9) without daylight saving, 23:30 begins the next day’s Rat hour. Historical clock rules shift this boundary. Birth-location longitude and the equation of time are not included; overseas local times are not automatically converted.
- Korean daylight saving in 1948–1951, 1955–1960 and 1987–1988, and the 127.5° E standard used in 1954–1961, are handled automatically.
- If you only know a two-hour period, select from clock-time ranges for the birth date. Rat hour is normally 23:30–01:30, Ox hour 01:30–03:30, and daylight saving shifts them one hour later. The midpoint is used with the same adjustments.
- Korean lunar dates are converted using calendar data aligned with the Korea Astronomy and Space Science Institute.
What changes when birth time is unknown
- Choosing “Time unknown” excludes the hour pillar, its Ten Gods, hidden stems and life stage, and any relationships involving it. Element balance, strength, the useful element and fortune scores are recalculated from three pillars, so the overall reading may change.
- For unknown birth times, the calculation library uses a noon reference to determine the year, month and day pillars and decade cycles. This does not recover your actual birth time. Near solar-term or date boundaries, the chart and decade-cycle start may differ from a calculation using the actual time.
Day Master strength and useful elements
- The month branch receives a weight of 3 and the day branch 1.5. Hidden-stem day proportions are included when measuring peer and resource energy supporting the Day Master.
- That ratio determines very weak, weak, balanced, strong or very strong categories. Balancing and seasonal temperature rules select useful, supportive and challenging elements.
Scores for each period
- We calculate Ten Gods, useful or challenging elements, and life stages for the period’s stem and branch relative to the Day Master.
- Area weights combine branch combinations, three-harmony groups, clashes, punishments, resentment, harm and breaks; stem combinations and clashes; and symbolic stars including Peach Blossom, Travel Horse, Canopy, helper stars, Red Matchmaker and Yang Blade.
- The transformation is round(60 + 40 × tanh((raw score − baseline) ÷ width)), capped at 8–99. Baseline and width vary by period. Scores do not represent actual performance or success probabilities.
- Daily weighting is day 70%, month 20%, year 10%. Monthly weighting is month 60%, average daily score 25%, year 15%. Annual weighting is year 68%, decade cycle 32%.
Why scores in the 50s and 60s are common
- Positive and negative factors can offset each other, while averages across days or areas concentrate values near the middle. The tanh transformation also softens extremes.
- The daily overall raw score uses weights of work 1, money 1, love 1, movement 0.6, well-being 0.9, relationships 0.8 and study 0.6, then multiplies by 1.35. Its baseline is 1.03 and width 4.4. A raw score of 0 is about 51; 1.03 becomes 60.
- Character game stats use round(50 + (area score − 60) × 2.2 + job adjustment), capped at 1–99. Ordinary fortune and ranking scores do not use this game adjustment.
How Tojeong differs from annual saju
- Saju builds a natal chart from the birth date and time, then compares Ten Gods, elements, combinations, decade cycles and annual cycles.
- Traditional Tojeong is a separate system. Age, birth month and birth day determine upper, middle and lower numbers, selecting one of 144 annual and monthly readings without using the birth hour.
- Both provide annual and monthly interpretations, but their rules and texts differ. The free Tojeong tool calculates its own reading code and presents an annual overview plus twelve Korean lunar-month texts.
How explanations are selected
- The factors contributing most strongly to each area determine its explanatory text. When several wording variants are available, the chart key and date select one deterministically.
What is tested, and what the readings do not establish
- Tests cover date conversion, solar-term and time boundaries, unknown-time handling and consistent calculations. Public fictional examples use the same engine as the calculators.
- These tests do not establish predictive accuracy. Scores express this service’s interpretation rules, not actual chances of success or a person’s ability or worth.
- Other sites may use different time corrections, solar-term conventions and interpretation weights. Compare the inputs and calculation methods before comparing results.
Service identity and content
- The English service name is K-Fortune. Content is written and edited under the K-Fortune editorial team credit.
- There is no account registration or payment for results. Birth details are calculated in the browser, and device storage is optional. The privacy policy explains advertising and visit analytics.
Tojeong reference: Encyclopedia of Korean Culture · Tojeong
Data and libraries
- Solar-term and stem-branch calculations: lunar-javascript (astronomical algorithms)
- Korean lunar-date conversion: korean-lunar-calendar (KASI-aligned calendar data)
- Saju explanations: K-Fortune editorial team, based on common interpretations in traditional saju literature
- Tojeong text: molpass/mcp-tojeong, an MIT-licensed Korean edition with an English translation for this site. The provider describes this edition as a modern-spelling revision, made in 1998, of materials in a private collection. Bibliographic details of those materials and expert review are unverified. K-Fortune has not compared all 144 readings with historical source texts.
Saju readings are reflection and planning content. Consult qualified professionals for important health, legal or investment decisions.
Updated 2026-10-16