Kua Number Calculator 命卦

Birth date and gender in — your Ming Gua (life trigram), East/West group and the four classically favourable directions come out, computed entirely in your browser. The year boundary is the actual Lichun instant, not a calendar-year guess. Free, no signup, zero network requests.

命卦 Ming Gua · 東四命 East group · 西四命 West group · 立春 Lichun boundary

Why most Kua calculators get February birthdays wrong

The Kua formula's "year" runs from one Lichun （立春，around February 3–5） to the next — not January 1 to December 31. Born on 3 February 2024, you belong to Lichun year 2023 and your Kua is 4 (Xun 巽); born on 5 February 2024 you belong to 2024 and your Kua is 3 (Zhen 震). Calculators that feed the calendar year straight into the formula quietly give every early-February birth the wrong trigram.

This page resolves the boundary with the kernel's DE441-based solar-term engine — the same astronomy behind our solar-term tables, cross-checked against the Hong Kong Observatory for 1901–2100 — and shows you the exact Lichun instant it applied to your date. The hour and minute fields matter only if you were born within hours of Lichun itself.

The formula, in the open

• Male 男：(2000 − Lichun year) mod 9; remainder 0 counted as 9.
• Female 女：(Lichun year − 2000 + 6) mod 9; remainder 0 counted as 9.
• Number → trigram: 1 Kan 坎 · 2 Kun 坤 · 3 Zhen 震 · 4 Xun 巽 · 6 Qian 乾 · 7 Dui 兌 · 8 Gen 艮 · 9 Li 離.
• Number 5 has no trigram: substituted per the convention you choose (standard: male→Kun, female→Gen; alternative: both→Gen). The result is labelled when substitution occurred — the kernel refuses to hide a school difference.
• Favourable directions: computed by treating your Ming Gua as the house trigram and flying the Great Year cycle (大游年) — which our kernel derives twice, from the memorised verse (A) and from the line-change method (B), and cross-checks palace by palace.

FAQ

What is a Kua number (Ming Gua)?

Your Kua number — Ming Gua （命卦）, the life trigram — is a number 1–9 (with 5 substituted) derived from your birth year and gender in the Eight Mansions （八宅） school. It sorts you into the East or West group and determines the four directions classically read as favourable for you and the four read as unfavourable.

How is the Kua number calculated?

For males: (2000 − birth year) mod 9, remainder 0 counted as 9. For females: (birth year − 2000 + 6) mod 9, remainder 0 counted as 9. The birth year is the Lichun-based year, not the calendar year. Numbers map to trigrams: 1 Kan, 2 Kun, 3 Zhen, 4 Xun, 6 Qian, 7 Dui, 8 Gen, 9 Li.

Why does the Lichun boundary matter for my Kua number?

The formula's year runs from Lichun (around February 3–5) to the next Lichun, not January 1 to December 31. Someone born on 3 February 2024 belongs to Lichun year 2023 and gets Kua 4 (Xun); born two days later they belong to 2024 and get Kua 3 (Zhen). Calendar-year calculators silently give the wrong number to everyone born in early February. This calculator resolves the boundary with the same DE441-based astronomy as our solar-term tables and shows you the exact Lichun instant it used.

What happens when my Kua number is 5?

The number 5 has no trigram of its own, so tradition substitutes a palace for it — and the two transmitted conventions differ. The standard one lodges males with 2 (Kun) and females with 8 (Gen); the other lodges both with 8 (Gen). Rather than silently choosing, this calculator exposes both under a toggle and labels the result when substitution occurred.

What are the East and West groups?

The eight trigrams split into East four （東四：坎震巽離） and West four （西四：乾坤艮兌）. In Eight Mansions practice, each person's favourable directions are those belonging to their own group, and house-person matching （宅命配） compares the dwelling's trigram with the occupant's.

Is the Kua number the same as my BaZi year pillar?

They are different systems that share the Lichun boundary. The BaZi year pillar is a ganzhi (e.g. 丙午) covering the whole Lichun year; the Kua number is a single Luoshu digit with a gender term. Both are computed by this engine — try the four-pillar calculator for the BaZi side — each labelled with its own ruleset.

Does my Kua number decide my luck?

No. This calculator computes the traditional numbers and the classical favourable/unfavourable direction labels exactly. Treating those labels as fortune is interpretation, not calculation. We make no predictions — this is a calculation tool for a cultural tradition, for research and education.

Is my birth data sent anywhere?

No. The Kua number is computed by a WebAssembly kernel inside your browser — the page makes zero network requests after loading, and nothing you type leaves your device. The same kernel binary powers our public API.

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