Sukuyo Astrology: Birth Mansion Calculator
Sukuyo is the 27-mansion calendar system handed down in Japan. Your birth mansion depends only on the month and day of your birth date in the old lunisolar calendar, so no birth time or place is needed. Each step of the calculation is shown so you can check it yourself.
The ring of 27 mansions
The 27 mansions form a ring that starts at Hairy Head. The Ox mansion, which sits between Dipper and Girl in the 28-mansion system, is left out in Sukuyo. Select any mansion to read about it and see its relationships.
All 27 mansions
- 1Hairy Head (昴)
- 2Net (毕)
- 3Turtle Beak (觜)
- 4Three Stars (参)
- 5Well (井)
- 6Ghost (鬼)
- 7Willow (柳)
- 8Star (星)
- 9Extended Net (张)
- 10Wings (翼)
- 11Chariot (轸)
- 12Horn (角)
- 13Neck (亢)
- 14Root (氐)
- 15Room (房)
- 16Heart (心)
- 17Tail (尾)
- 18Winnowing Basket (箕)
- 19Dipper (斗)
- 20Girl (女)
- 21Emptiness (虚)
- 22Rooftop (危)
- 23Encampment (室)
- 24Wall (壁)
- 25Legs (奎)
- 26Bond (娄)
- 27Stomach (胃)
Compare two people and see the 27×27 table
Method and version
- Source: the 27-mansion framework comes from the Sukuyō-kyō (Xiuyao jing), the esoteric Buddhist scripture Kūkai brought to Japan. This site only assigns mansions by calendar and writes symbolic readings; it does not replace the scripture.
- Calendar: Japanese Tenpo calendar rules with new moons fixed in Tokyo time, covering 1900–2100. All four languages use the same method, so a birth date gives the same mansion in every language.
- Month-start mansions: the first day of each old-calendar month is assigned a fixed mansion — month 1 Encampment, 2 Legs, 3 Stomach, 4 Net, 5 Three Stars, 6 Ghost, 7 Extended Net, 8 Horn, 9 Root, 10 Heart, 11 Dipper, 12 Emptiness (National Astronomical Observatory of Japan, calendar wiki).
- Counting: from the month-start mansion, move around the ring by the day of the month minus one. Each month restarts from the table, so two neighbouring days can skip a mansion or share one.
- Leap months restart from the month-start mansion of the month they repeat.
- 2033–2034: the Tenpo rules have no unique answer in this window, so month numbering follows a stated convention and the result page marks it.
- Chinese lunar calendar: it fixes new moons in Beijing time, so the first day of some months falls one day apart from Japan, and leap months can be placed differently. On those dates the result page lists both mansions side by side.
- A birth mansion is a label assigned by the calendar table, not the measured position of the Moon on the day you were born.
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FAQ
Why is no birth time or place needed?
The birth mansion depends only on the old-calendar month and day. Everyone born on the same date shares a birth mansion, so the birth date is enough.
Why did another site give me a different mansion?
Usually because of the calendar method. Some sites use the Chinese lunar calendar (Beijing time), while this tool uses the Japanese Tenpo calendar (Tokyo time). When a new moon falls one day apart, or a leap month is placed differently, the mansion shifts by one. We show both mansions on such dates. A miscopied month-start table is the other common cause.
How do the 27 and 28 mansions relate?
The 28-mansion system has an extra Ox mansion between Dipper and Girl. Sukuyo uses 27, so Ox never appears here. The "mansion of the day" on our almanac pages follows a different daily rule; the two cannot be converted into each other.
Is the mansion description about me personally?
No. Everyone with the same birth mansion sees the same description. It sums up this site’s symbolic interpretation of its name and sky imagery and is offered as one lens for reflection, not as a judgement about you.
Do I need an account or to pay?
No. Birth mansions, compatibility and the full table are free to view, with no sign-in and no need to give your gender or name.