Flying Star Calculator 玄空飛星

Enter a construction year and the sitting direction — the nine-palace Xuan Kong natal chart (mountain, facing and period stars) is computed entirely in your browser by the same cross-checked kernel that powers our public API. No signup, zero network requests.

Xuan Kong Fei Xing 玄空飛星 · sitting 坐山 · facing 向首 · period 運

Reading the chart

Each palace shows the mountain star and facing star side by side (larger numerals, top row) with the period star beneath (smaller, dashed divider). Stars highlighted in the accent colour equal the chart's period — the classical "prosperous" star. The sitting and facing palaces are outlined.

Four placements carry names in the tradition, and this calculator labels them mechanically from the chart — no interpretation is added:

• 到山到向（旺山旺向） wang shan wang xiang — the timely mountain star reaches the sitting and the timely facing star reaches the facing; classically read as the ideal placement.
• 双星会向 shuang xing hui xiang — both timely stars gather at the facing.
• 双星会坐 shuang xing hui zuo — both timely stars gather at the sitting.
• 上山下水 shang shan xia shui — mountain star at the facing and facing star at the sitting ("mountain up, water down"); classically read as misplaced. Partial variants are labelled 下水 (only the mountain star misplaced) and 上山 (only the facing star misplaced).

How this is computed

• Period from date, not guesswork. The 20-year cycles are anchored at 1984 = start of Period 7; the year flips at the exact Lichun instant (same DE441-based astronomy as our solar-term tables). A house dated 3 February 2024 is still Period 8 — the chip above shows you the boundary the kernel applied.
• Mountain & facing stars fly by the 24 mountains. The period-star number occupying the sitting palace enters the centre as the mountain star (likewise the facing palace for the facing star); whether each then flies forwards or backwards is decided by the yin or yang of the yuan-dragon mountain matching that star's original palace and class — with the five-yellow special case resolved by the sitting/facing mountain itself. That table is grade-A data in the kernel and asserted by property tests.
• 下卦 and 替卦 both included. Substitution (替卦, the 坤壬乙 mnemonic) applies in the 3°-wide bands beside each boundary; the kernel implements it from collated grade-A tables, and its self-test asserts a substitution chart actually differs from the standard one.
• Same kernel everywhere. This page runs the identical WASM binary as the chart verifier and the public API — same input, same bytes. Engine version and ruleset ids are shown with every result.

FAQ

What is flying star feng shui (Xuan Kong Fei Xing)?

Xuan Kong Fei Xing （玄空飛星） maps a building to a 3×3 grid of nine palaces. Each palace holds three stars: the period star (from the 20-year construction cycle), the mountain star (back of the building, governs people and health) and the facing star (front, governs money). The stars fly forwards or backwards through the palaces according to fixed rules, and their placement is read against the current period.

What is Period 9, and when does it run?

The 20-year cycles (yun) are anchored so that 1984 begins Period 7, making Period 8 run 2004–2023 and Period 9 run 2024–2043. Years flip at Lichun (around February 4), not January 1: a house completed on 3 February 2024 still belongs to Period 8, while one completed after Lichun on 4 February 2024 belongs to Period 9. This calculator applies the Lichun boundary using the same astronomical kernel as our solar-term tables.

How do I determine my house's period (yun)?

Traditionally the period is set by when the building was completed, though some lineages use the move-in date or the last major renovation. Sources genuinely disagree, so this calculator takes the date you supply and tells you exactly which period boundary it falls on. Our dispute register documents the completion-vs-move-in debate rather than hiding it.

What is the difference between sitting (zuo) and facing (xiang)?

The sitting （坐山） is the back of the house — the side it leans against; the facing （向首） is the front, always the sitting plus 180°. A house that faces south sits north （子山午向）. If you have a compass bearing, our 24-mountains converter turns it into the mountain name this calculator asks for.

What is the difference between xia gua and ti gua charts?

Xia gua （下卦） is the standard chart used whenever the sitting falls comfortably inside one of the 24 mountains. Ti gua （替卦） substitutes certain stars with the 坤壬乙 mnemonic when the sitting sits close to a boundary line — the last 3°-wide bands on each side of a mountain. Both are implemented in our kernel from grade-A collated tables, and this calculator can render either.

Does the chart tell me if my house is lucky?

No. This tool computes the traditional chart exactly and shows its classical pattern labels (such as 旺山旺向 or 上山下水). Reading those labels as fortune is interpretation, not calculation. We make no predictions — this is a calculation engine for a cultural tradition, for research and education.

Is this flying star calculator really free?

Yes — no account, no email, no limits. The chart is computed by a WebAssembly kernel inside your browser; the page makes zero network requests after loading, and your inputs never leave your device. The same kernel, byte-for-byte, powers our public API.

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