Saju guide
Saju vs BaZi: one chart, two traditions
Saju and BaZi are the Korean and Chinese names for the same Four Pillars chart. The math is identical; the vocabulary and the way people use it differ.
· 3 min read
The short answer
Saju and BaZi are the same system. Both turn a birth moment into four pillars of a heavenly stem and an earthly branch, eight characters in total, and read them through yin and yang and the five elements. If two practitioners use the same birth time conventions, your Saju chart and your BaZi chart are identical, character for character.
The names describe the same chart from two angles. Saju (사주, 四柱) is Korean for “four pillars.” BaZi (八字, bāzì) is Chinese for “eight characters.” The full Korean term, saju palja (사주팔자), joins both. Japan has the same system under the name shichū suimei (四柱推命).
What is identical
Everything that goes into building and structuring the chart is shared:
- The ten heavenly stems, the twelve earthly branches, and the cycle of sixty.
- The solar calendar: the year starts at the solar term Ipchun (around February 4) and each month starts at a solar term.
- The five elements with their generating and controlling cycles.
- The Day Master as the center of the chart, and the Ten Gods that describe every other character's relationship to it.
- Ten-year luck pillars and yearly pillars for timing.
- Combinations and clashes between stems and branches, used for compatibility.
Where the traditions differ
The differences are in language, emphasis, and culture rather than in the chart.
Vocabulary. Korean practice reads the characters in Korean (甲子 is gapja rather than jiǎzǐ) and has its own everyday terms. Koreans talk about their gunghap (궁합) where Chinese practice speaks of hehun (合婚), and Korean readings often feature sinsal (신살), symbolic stars such as dohwasal (도화살, the “peach blossom” of charm and popularity) and yeongmasal (역마살, the restless “post horse” of travel and change).
Time correction. Both traditions debate whether to use clock time or true solar time. In Korea the gap is about 30 minutes, because Korea Standard Time is set for 135°E while most of the country lies near 127°E. China uses a single time zone for the whole country, so in the far west the gap can reach about three hours.
The midnight hour. The 子 (Rat) hour runs from 11 pm to 1 am, straddling midnight. Some schools in both countries split it so that births between 11 pm and midnight keep the same day pillar (in Korean, yajasi and jojasi); others change the day at 11 pm. A birth in that hour can get a different Day Master depending on the convention.
Everyday use. In Korea, Saju is woven into ordinary life: gunghap before marriage, New Year readings, saju cafés, and apps. BaZi practice in Chinese-speaking communities is often paired with feng shui and date selection for business and family events.
Side-by-side glossary
| Concept | Saju (Korean) | BaZi (Chinese) |
|---|---|---|
| Name of the system | 사주 saju, 사주팔자 saju palja | 八字 bāzì, 四柱 sìzhù |
| Day Master | 일간 ilgan | 日主 rìzhǔ |
| Heavenly stems | 천간 cheongan | 天干 tiāngān |
| Earthly branches | 지지 jiji | 地支 dìzhī |
| Five elements | 오행 ohaeng | 五行 wǔxíng |
| Ten Gods | 십성 sipseong | 十神 shíshén |
| Luck pillars | 대운 daeun | 大运 dàyùn |
| Useful element | 용신 yongsin | 用神 yòngshén |
| Compatibility | 궁합 gunghap | 合婚 héhūn |
| Zodiac animal | 띠 tti | 生肖 shēngxiào |
Which one should you use?
If you already have a BaZi reading, you already have your Saju chart: the interpretation may sound different, but the eight characters are the same. Choose by the style of reading you enjoy. Korean Saju readings tend to focus on personality, relationships, and compatibility in everyday language, which is the approach OtterPrism takes.