South Korea
Korean Saju (Four Pillars)
Computes from: Birth date and birth hour.
You get: Your four pillars (eight characters), Day Master and Five Elements balance, explained in plain English.
Six traditions, six free calculators
One card per system: where it comes from, what it needs, and what you get.
Indonesia (Java)
Weton and Neptu
Computes from: Birth date. A second date adds couple matching.
You get: Your weekday and pasaran (5-day market cycle), your neptu number, and a Primbon-style jodoh (couple) category.
Japan
Kyusei Kigaku (Nine Star Ki)
Computes from: Birth date. The year turns at Risshun (about February 4), not on January 1.
You get: Your honmei star among the nine stars, plus how it compares with Korean Saju.
India
Vedic Moon Sign and Nakshatra
Computes from: Birth date, birth time and the time zone of the birth place.
You get: Your Moon sign (Rashi), nakshatra and pada, using the sidereal Lahiri method.
Guatemala and Mesoamerica
Maya Tzolk'in
Computes from: Birth date.
You get: Your Kin number, day sign (nawal) and trecena from the 260-day count.
Thailand
Thai Birthday Color and Buddha Posture
Computes from: Birth date (only the weekday matters).
You get: Your birthday color and guardian Buddha posture (Phra Prajam Wan Kerd).
Same birth date, different answers. The systems do not agree with one another because they measure different things: a weekday, a lunar position, a nine-year cycle or a 260-day count. Comparing them is the point of this page.
Want the full Korean Saju reading?
The calculators above give a first result. A full Saju reading reads your Day Master, Five Elements balance and 10-year luck cycle from your exact birth data.
See my Saju reading — $7.99 →Frequently asked questions
How do these fortune calculation systems differ?
Each tradition starts from a different clock. Saju uses year, month, day and hour to build eight characters. Weton combines a 7-day weekday with a 5-day pasaran cycle. Kyusei Kigaku reduces the birth year to one of nine stars. The Vedic method reads the sidereal Moon. The Tzolk'in counts a 260-day cycle. The Thai system maps the weekday to a color.
Which calculators need my birth time?
Only two. Korean Saju uses the birth hour, and the Vedic Moon sign and Nakshatra calculator needs the birth time and the time zone of the birth place. Weton, Kyusei Kigaku, Maya Tzolk'in and the Thai day color work from the birth date alone.
Are the calculators free?
Yes. Every calculator here is free and needs no signup. Deeper paid readings are offered separately for some systems, and the free result never depends on buying one.
Are the results predictions?
No. These tools are for education and self-reflection. The calendar arithmetic is computed exactly, but the meanings come from traditional interpretations, which differ by source and community.
Why are some calculator pages not in English?
Each page is written in the language of its tradition where a native-language page exists. Saju, the Vedic calculator and the Thai day color have English pages. Weton is in Indonesian, Kyusei Kigaku in Japanese, Maya Tzolk'in in Spanish and Portuguese, and the Vedic calculator also has a Hindi page.
These calculators are for education and self-reflection. They are not predictions and not a substitute for professional advice.