Free BaZi calculator: your chart, read the Korean way

Is BaZi the same as Saju?

The chart is the same; the reading has an accent. BaZi is the Chinese name, Saju the Korean one, and Shichu Suimei the Japanese one — all three read four pillars of two characters each, derived from the same Xu Ziping method that put the day master at the centre. Anyone trained in one tradition can read a chart produced by the other, and nothing on this page will contradict a Chinese calculator’s pillars.

What does differ is emphasis, and a few conventions worth knowing:

• True solar time. Korean practice is unusually strict about it, because Korea’s standard time is set to a meridian east of the country: noon by the clock in Seoul is about 11:28 by the sun. Many Chinese calculators apply the same correction for China’s single time zone; some skip it entirely. This site always applies it, from the longitude of your birth city.
• The 23:00 day boundary. Both traditions debate whether the day turns at 23:00 with the rat hour (야자시 / 조자시 in Korean) or at midnight. We use 23:00 and warn you when your birth falls in that hour, because that is where charts legitimately diverge.
• Vocabulary. The ten gods, the useful god and the climate principle are shared, but the Korean names differ: 십신 (ten gods), 용신 (yongsin, the useful element), 조후 (johu, the climate of the chart), 대운 (daeun, the ten-year luck pillars).
• Where it is used. In Korea a chart is a normal part of everyday life — consulted before a marriage, at New Year, or over coffee in a 사주카페 — rather than a specialist’s subject.

What this calculator gives you

Your four pillars with their stems, branches, elements and ten gods; your day master and what it means; the hidden stems inside each branch; your five-element balance counted both visibly and with hidden stems; and your ten-year luck pillars with the ages they run. Everything is computed, not looked up in a table: the year and month pillars come from the sun’s apparent ecliptic longitude at your birth moment, and the day pillar from a continuous day count, so any birthplace and any year works.

The engine is checked against 60,000 randomly generated charts from an independent implementation, with no differences — if a pillar here disagrees with your usual calculator, the likely cause is a different day boundary or a missing solar-time correction, and the chart page shows you both times so you can tell which.

Reading your chart

Find the day pillar; its upper character is you. Read the ten day masters to see what yours means, then look at the season you were born into, which decides whether that day master is supported or stretched. The four pillars guide walks through each pillar, and what is Saju covers the system from the beginning.