BaZi Calculator - Four Pillars

Enter a birth date and time to see your Saju chart at a glance: the eight characters, with the Five Elements, Ten Gods and major luck cycles.
Everything is calculated on your device. No sign-in, and no in-app purchases.

This app is not made or run by any government agency and does not represent any government. Sources for the lunar calendar and solar terms are listed under "Sources" below.


■ What you can see

- Your eight characters, in Chinese characters with Korean readings.
- Year, month, day and hour pillars, Ten Gods, hidden stems and the twelve life stages.
- Five Elements balance, yin and yang, zodiac animal, lunar birthday.
- A Day Master reading, element balance, ten major luck cycles and this year's luck.
- Save or share a chart as an image card.
- Save charts for family and friends by name.


■ How it is calculated

Saju apps often disagree because they use different rules. This app shows its rules on screen.

- Year and month change at the exact minute each solar term begins.
- Solar term times come from astronomical calculation, checked against the Korea Astronomy and Space Science Institute.
- The lunar calendar comes from the Korea Astronomy and Space Science Institute, from 1900 to 2050.
- Your birth time is adjusted to the real sun time where you were born (local mean solar time). You can turn this off.
- Years when Korea used a different time zone (1908-1911 and 1954-1961) and daylight saving time are taken into account.
- You choose whether a birth between 23:00 and midnight belongs to the same day or the next.
- If the birth time is unknown, the hour pillar is left empty rather than guessed.


■ Privacy

Names and birth details are stored only on this device and never sent anywhere.
The internet connection and advertising ID are used only to show ads and send usage statistics.


■ Sources

This app is made by an independent developer. It is not affiliated with, and does not represent, any government agency. The lunar calendar and solar terms are based on the official data below.
- Lunar dates (1900-2050): Korea Astronomy and Space Science Institute, lunar calendar data, Public Data Portal https://www.data.go.kr/data/15012679/openapi.do
- Solar term check: Korea Astronomy and Space Science Institute, special day data, Public Data Portal https://www.data.go.kr/data/15012690/openapi.do
- Lunar and solar date conversion: Korea Astronomy and Space Science Institute https://astro.kasi.re.kr/life/pageView/8

Readings are for reference only, not a basis for medical, legal or financial decisions.

Recent changes:
- Stability and usability improvements.