About BaZi Compass

BaZi Compass is an independent, free educational project. We exist to make BaZi — one of China’s oldest cultural thinking tools — approachable for readers who grew up outside that tradition, with the same care, honesty and nuance a good Chinese tutor would bring.

What we do

• Cast charts free. The Four Pillars, hidden stems, ten stars, Na Yin, element balance, Qi Yun and the full Da Yun timeline are available to everyone with no account and no payment.
• Explain, not predict. Our readings are plain-English interpretations written in the conventional school of BaZi, clearly labeled as cultural reflection rather than fate.
• Stay private. Chart casting runs entirely in your browser. We do not collect birth data, and we have no accounts.

Methodology

Calculations use the open-source tyme4ts engine (6tail, MIT license), the same calendar logic widely used in Chinese almanac software. The conventions we follow:

• Year Pillar changes at 立春 (Start of Spring).
• Month Pillar follows the twenty-four solar terms.
• Hour Pillar uses the two-hour branch system; 晚子时 follows the tyme4ts default.
• Qi Yun and Da Yun use tyme4ts default child-limit and decade-fortune providers.
• Ages in the timeline use the traditional 虚岁 (nominal) reckoning.

Our engine is calibrated against documented examples and cross-checked against a second independent calendar library (lunar-typescript) across twenty boundary cases — season-change days, solstices, late-night hour-boundaries, leap-month years and more. You can run the checks yourself: npm run calibrate.

Transparency notes

• Exact birth-time correction (true solar time, by longitude and equation of time) is not yet applied; current times are read as clock time. This is a documented roadmap item.
• Short “unlock after watching an ad” gates on some Da Yun chapters help keep the site free. Your unlock stays on your device (localStorage) and is permanent for that chart on that device.
• We respect the culture this system comes from. We use Chinese terms alongside English, and we never dress folklore up as science.

Behind the Compass

BaZi Compass is maintained by Harry Liu, a Chinese-culture enthusiast dedicated to sharing the ancient teachings of the East in clear, honest English.

BaZi Compass is Harry Liu’s way of sharing China’s ancient tradition with readers who grew up outside it. The project runs on one conviction: that this heritage deserves an explanation that is faithful to the classics and honest about its limits — a mirror for reflection, not a script to obey. Everything here is hand-built to make the old art of reading the Eight Characters approachable for a modern reader, with calculation that is fully transparent and interpretation that is always clearly a cultural lens.

Last updated: September 2026.

Contact

Questions, corrections or licensing inquiries:[email protected].

Or use the contact page — we reply within a few business days.